Lung Neoplasm

BRONCHOGENIC CARCINOMA
#1 cause of death from malignancy in men & women
Breast Ca still more common in women, less mortality
Malignant Neoplasm that arises from bronch or alveolar epi
Not carcinoid, mucus gland tumors or mesenchymal
<0.5% arise from trachea, most from bronchi & lung
5 yr survival rate 10-15%
"S-sign of Golden" - bulge created by drowned lung
central portion pulled in by mass fibrosis
Eccentric calc may represent dystrophic calc of nec portion
up to 10% calc
"Tail Sign" - assoc w desmoplastic rxn, nonspecific

Risk Factors - 10X w smoking, dec gradually w time
Asbestos 5X alone, 50X combined w smoking
Steel coke, arsenic, chromium, chloromethyl ether, rad
Radon from industrial & home exposure - 20,000 per yr
Fibrosis - TB, dif interstitial pulm fib, scleroderma etc
Genetic & concomitant Dz

Clinical Presentation - 10% asym, local sx #1, cough, pneumonia
Paraneoplastic Syn - cachexia, clubbing, inappropreate ADH
thrombophlebitis, non-bacterial thrombotic endocarditis

Staging
Ti - Ca in situ, rare
T1 - <3cm, none near main bronchus or pluera
T2 - abuting viscerl pluera, greater than 2cm from carina, causing atel or >3cm
T3 - Out of lung, within 2cm of carina without involving the carina
No vital structure invaded, resec poss
T4 - Vital structure invaded, no resection
vital includes esoph, carina, trachea, heart, vert body
Tx - malig eff or sputtum, stage IV automatically
N1 - intrapulmonary nodes, N2 - mediastinal, ipsilat only
N3 - any nodes in vicinity inc supraclavicular or scalene
M1 - any dist mets, only 1/3 of adrenal abn actually mets

Stage 1 - T2 N0 M0
Stage 2 - T2 N1 M0
Stage 3a - T3 N2 M0, last chance for resection
Stage 3b - T4 N3 M0, nonresectable
Stage 4 - M1 or Tx
1. Adenocarcinoma - 50%, arise in bronchiolar or alveolar epi
Gland formation, Papillary structures & Mucin production
Mucin or psammoma bodies seen on histo may calc
Destroys tissue as it grows, may be endobronchial
Slow to grow but early met, NOT best prognosis
Irreg & spiculated appearance, surrounding fibrosis
Borders can have any appearance, do not define malignancy
known to arises from previous scars, rarely cavitates
Weak assoc w smoking, can occur without smoking

Bronchioalveolar - a well diff type of adenoca w pneumonic pattern
spreads on existing bronchiol & alveolar walls w/o disruption
90% form single isolated nodule of ill defined density
can frag and redistribute forming mult foci
may Simulate Pnuemonia or a diffuse nodular pattern
Good prognosis if resected as solitary
NO assoc w smoking

2. Squamous Cell Ca - 35%, arises centrally in lobar or seg bronch
Rapid growth but met late, BEST prognosis
polypoid & grow into wall & lumen causing Cough & hemoptysis
grows thru wall & forms lobulated border
Hilar mass often w obs consol, keratin pearls on histo
more common in larger bronchi
Central nec freq, Cavitates if comm to bronchus established
Strong assoc w cig smoking, also called epidermoid

3. Small Cell Ca - 25%, arise centrally in main or lobar bronch
Kulchitscky cell origin - bronchiol neuroendocrine cells
malignant variant or carcinoid, tight cells w no cyto
freq mytosis seen on histo not seen w carcinoid
neurosecretory granules seen on Elec Micro key to Dx
Produces most of the paraneoplastic syndromes
ectopic ACTH & ADH
Only ectopic parahormone is produced by squamous cell
Smooth endobronchial component, early peribronchial invasion
extrinsic compression & obs produced
Lymphatics invaded early, enlarged nodes lead to hem spread
hilar mass often larger than I', never cavitate
SVC obs a freq feature
Strong assoc w smoking
4. Large Cell Ca - 15%, non sm cell not squamous or adeno by histo
Dx of exclusion, usually peripheral & Lg at time of Dx, >3cm
Poorly differentiated, rapid growth, early met, poor prog
freq central nec
Weak assoc w smoking sim to adenocarcinoma

Giant Cell - subtype, bizarre shaped giant cells w RBC in cyto
very aggresive w pronosis sim to Sm cell

5. Pancoast's Tumor - Squamous or adeno ca arising in sup sulcus
portion of apex indented superiorly by subclavian art
Dx by Sx - invasion into brachial plexus & sym gang chain
arm pain & horners syn, vert invasion also freq
CXR - apical fibrous cap >5mm & rib destruction #1

RARE PRIMARY NEOPLASMS OF THE LUNG
1. Bronchial Adenomas - true bronchial gland adenomas do occur but rare
Carcinoid - 90%, low grade malig w no assoc w smoking
Most are Central and present w hemoptysis, 90% are <50yrs
arterial spasm assoc w nodule, causes perfusion defects
Neurosecretory granules present, source of II' Sx
Possible in spectrum of Kulchitsky Cell
Has more Granules in cell cyto than Sm Cell, rare met
Bronchoscopy - Slow growing, allows covering of resp epi, "Iceberg"
CT & CXR - Very marginated, more visible on endoscopy
Calc in 30%, Most seenpathologically, rarely seen w plainfilm
Present as recurrent pneumonia etc, 15% met to local nodes
Atypical Carcinoid - Kulchitsky Cell Ca Type II, 25% of carcinoids
usually >2.5cm & occur in older pts, 50% present w nodal mets

Adenoid Cystic Carcinoma - Cylindroma, #2 in Trachea
Also slow growing w resp epi cover, sharply marginated
Often locally invasive due to lack of Sx, 75% obs needed
Local nodal met poss but rare extrathoracic

Mucoepidermoid Carcinoma - Variable aggresive, usually low
Abundant mucinous cysts & solid collections of squa cells
Slow growing w epi cover, can be exophytic
3. Mixed Tumors
Carcinosarcoma - aggressive w local invasion & dist mets early
Epithelial & Mesenchymal components seen in same tumor for Dx
Most peripheral lg mass w nec & hem
Central endobronchial type may sim mucous plug

Pulmonary Blastoma - aggressive, sim to Carcinosarcoma
Epithelial lined tubules in primitive stroma
simulates embryonic lung formation
Well differentiated form has better survival

Pleuropulmonary Blastoma - Aggressive childhood form, fatal
Solid & Cystic areas w no epithelial component
Presents as pneumonia w extensive chest involvement

Intrathoracic Lipoma - 5:1 male, rare I' in lung parenchyma
assoc w major bronchi, rounded & do not change shape
if extrapulmonary they will change shape
CXR - difficult to see do to low density

PULMONARY INFECTIONS
Bulging fissures - all bacterial inf, also Ca w drowned lung
Pneumatoceles - staph, pneumococcus, klebsiela
more common in child, esp w staph
Pneumonia w enlarged hilum - TB HISTO,
Alcoholic pts - Inc cavitation & G-, TB, sepsis
25% mortality if elderly, septic or assoc w other Dz
Adenopathy - frequently present in children, rare in adults
coccidio assoc w adenopathy indicates dissemination, need Tx

COMMUNITY AQUIRED
G+ BACTERIAL

1. Strep Pneumonia - 75%, seen in extremes of life, <5 & >60yrs
Homogeneous lobar consolidation, usually lower lobe
Air bronchograms, M>F, multilobulated w Inc mortality
Sepsis assoc w lg effusions
Very rapid clinical onset of fever & cough etc

2. Staph - assoc w unique clinical setting, nosicomial freq
II' inf to viral or emboli in IV abusers
Cavities & pneumatoceles - often assoc in children
Klebsiella & E. coli also supparative infections assoc w pneumatocele
Empyema & Abcess - more common in adults
Rarely primary, bilat & patchy consol, lower lobes #1
Rapidly progressive

3. Strep Pyogenes - Rare, Large pleural effusions very common

4. Actinomycosis - G+ bacteria that contains sulfur granules
filamentous & branching growth pattern, sim fungus
occurs II' to mucosal damage from trauma, iatrogenic etc
forms an aggressive granulomatous infection
rib destruction, eff, mass, and fistulas, R lung>L
often crosses intralobular fissures
proteolytic enzymes elaborated, sulfur granules assoc
GI involvement more common than lung (60%)
also seen in uterus II' to IUD use

5. Nocardia - Aerobic & G+ bacteria but forms hyphae in tissue
CXR - airspace pneumonia & cavitation, solitary mass poss
May induce Alveolar Proteinosis, often assoc w SLE in males
inhaled from contaminated soil

G- BACTERIAL - 20% community aquired
more common than Strep for immune compromised pt

1. Klebsiella - >50y/o, Etoh & aspiration unsual source, immusupressed
Rhinoscleroma - chronic infection sinuses, pharynx & trachea
gran tissue errodes turbinates, transglottic stenosis
Freidlander's Pneumonia - Bulging Fissure sign
Common cause of cavitation

2. H flu - assoc w chronic pulm Dz, empyema & bacteremia rare
encapsulated strains more severe

3. Mycoplasma - Atypical pnuemonia, resembles viral infection
Can cause otitis in kids, adenopathy freq in kids
most cases not detected
Extrapulmonary manifestations - myalgia, hemolytic anemi

4. Pseudomonas - usually nosicomial, high mortality, aspirated bugs #1
airway dissemination, nec & cavitation, plueral
forms patchy nodular consolidations in lower lobes, NOT lobar
represent microabcesses that coalesce
can disseminate from kidney etc, more diffuse, uncommon

5. Legionella - G- w similar clinical & CXR finding to S. pneumo
slower clinical onset, freq N WBC, freq assoc CNS Sx
Perdominante lower lobar airspace consolidation
progresses to multilobar consolidation
Plueral Effusion in 50%, Adenopathy very rare
Cavitation occurs more freq in immune compromised
Tx - Erythromycin usually works, CXR always worsens initially
complete clearing often takes months

PULMONARY ABSCESSES
Abcess - occurs within the lung, NO displacement of markings
Occur most often II' to aspiration, dissemination & pneumonia
tend to occur in dependent positions
usually round w thick wall & air-fluid level, indistinct margins
DDx - bronchoplueral fistula, oblong shaped
Tx - usually medical, tend to self-drain

Empyema - also oblong due to location in pluera
sharp thin interface, displaces adjacent lung
Tx - must be surgically or interventionaly drained
Aspiration Pneumonia - 37% result in empyema, most w abscess also
most of damage due to PH of <2.5, mixed flora

VIRAL INFECTIONS
Interstitial w freq alveolar edema & hemorrhage, eff rare

1. Adenovirus Infections - DNA virus, pneumonia rare
Interstial pattern most common

2. Varicella Pneumonia - rare, usually in adults
rare w zoster, lesions develop 2-3d P skin lesions
diffuse nodular infil, miliary type nodules
rapid prog to coalescent densites
occurs in 10% of adults, 2-5 days p onset of rash can
heal as mult sm calc

3. RSV - esp in kids & AIDS

4. Influenza Pneumonia - severe diffuse hemorrhaic pneumonitis
mortality 60-80%
occurs in <1% of infected induviduals

MYCOBACTERIAL INFECTIONS
inc incidence II' to HIV

1. Primary Tuberculosis - usually affects extreme age groups
95% no clinical evidence, or mild Sx resolve w/o Tx
Focal or Homogeneous air space consol, NO dominant distribution
Pulmonary focus of Gohn gran w nodes is Ranke Complex
often the only residue in addtion to positive PPD
Adenopathy - unilat or bilat always present in child
only 10% of adults, absent in reactivation TB (post-primary)
Pleural Effusion - high in PMN's, but rarely grow bugs
2/3 will go on to develop reactivation TB
10% w pos PPD get I' TB, 5% develop Reactivation TB

2. Reactivation TB - Apical or post segs
Caseous nec & cavitation w airway spread of bacilli
Aspergillomas commonly form in these cavities (mycetoma)
Miliary - hematogenous spread, usually critically ill
detected only w Bx, rare in sputum & often have Neg skin test
nodules similar size in acute phase
upper lobe nodules larger in chronic phase II' to ventilation
Endobronchial dz can lead to fistulas
Rasmussen's Aneurysm

3. Non-TB Mycobacterial Infections - Freq assoc w alcoholism
cavitary upper lobes & reactivation type nodules
cavities more likely to have thin walls
less likely to have empyema or effusion
nodules may imitate I' ca
diffuse pulm infiltrates in immunecompromised

ENDEMIC MYCOSIS
infect healthy host, equal upper & lower Dist
Hyphae produce spores which infect host, resolve spont
Unlike TB they do not reactivate, no life-long immunity
Rare cavitation or plueral eff
Macrophage & T-cell response most important

1. Histoplasmosis - #1, 5um yeast, heals with central Calc
Minimal initial response, No pneumonia, asym
allows for freq dissem to lymphnodes & spleen
Freq hilar & mediastinal adenopathy
Chronic - assoc w mediastinal Fibrosis & calc granulomas
May sim an invasive mass on CT, cause atel or vasc obs
60% heal w residual nodule, freq w central Calc
Fiborsing Mediastinitis - compresses SVC & pulm veins

2. Blastomycosis - 15um yeast, endemic more NE than histo
may have rebudding, NO calc, Rare adenopathy
Early pyogenic response w pneumonia prevents spread
Chronic - focal paramediastinal mass, rare invasive
Heals w no residual nodule
Disseminated form may go to Bone & GU

3. Coccidiomycosis - 60um yeast, by far the most virulent
releases hundreds of endospores, desert southwest
Early pyogenic response w pneumonia prevents spread
"Valley Fever" - acute hypersensitivity Rxn, stops disease
Adenopathy Rare, but bad sign if it does develop
Non-caucasian pt's tend to be more severly affected
Chronic - mult cavities w thick or thin walls, sim Sarcoma
40% heal w resid nodule, rare calc, diff DDx from Ca
Disseminated form may go to CNS & Bone

OPPORTUNISTIC MYCOSIS
Weak pathogens, compromised pt's

1. Aspergilla - second most common fungus, colonize 16% of N pts
Macrophage, PMN's & airway mech protection most important
Cystic Fibrosis & Asthma pt's susceptable
Rare dissemination in AIDS due to II' importance of T
Allergic Bronchopulmonary Aspergillosis - bronchi colonize
airway inflam w bronchial cuffing, bronchiectasis
Mucous Plugs - "Gloove Fingers" or "Toothpaste" shadows
Lobar shrinkage due to fibrosis late
Radiologic, peripheral eosionophils & Sputum make Dx
Mycetoma - Arise in Pre-existing cavities or TB, sarcoid
Asym ball in air space, residual Crescent of air
Hemoptysis common - fatal in 10%
10% resolve spontaneously, disseminate if pt compromise
Invasive Aspergillosis - assoc w neutropenia, fatal in 70%
Invade vasc causing infarcts, cause isolated infarcts
Air Crescent Sign now due to retracted "Lung ball"
actually a good sign that surrounding lung fighting
Return of granulocyte fxn needed to resolve
CT halo - assoc w surrounding "target" of infarct
Systemic dissemination to CNS etc
Chronic Necrotizing Aspergillosis - semi-invasive in tiss
NO vasc invasion, can still have hemoptysis
assoc w mild immune suppresion, NO mucoid impaction

2. Nocardia - Aerobic & G+ bacteria but forms hyphae in tissue
CXR - airspace pneumonia & cavitation, solitary mass poss
May induce Alveolar Proteinosis, often assoc w SLE in males
inhaled from contaminated soil

PULMONARY MANIFESTATIONS OF AIDS
HIV-1 most common form in US, HIV-2 in africa
CD-4 lymphocyte count directly related to type of infection
400-1000 - uncontroled bacterial infections begin occuring
300-400 - TB, Lymphocytic Interstitial Pneumonitis
200-300 - Kaposi's Sarcoma
100-200 - PCP
50-100 - Cryptococcus, NH Lymphoma
0-50 - M. Avium Complex

1. Viruses - Seen in 100% of homosexuals, ie sexually transmitted
CMV - Coexists in lung in absence of Dz, pneumonia rare
Implicated as cofactor in Kaposi's Sarcoma
Ebstein Barr Virus - B-cell adenovirus
Oncogenic, assoc w Burkitt's lymphoma, LIP & NHL

2. Fungus
Pneumocystis Carini - reclassified as fungus, pulm only
Most common pulm Dz, initial manifestation in 60%
Trophozoite attach to alveolocyte & insert sporozoites
seen as 10micron cup shaped clusters in cell
Mature & rupture releasing more trophozoites
Rupture assoc w outpouring of fluid into alveoli
CXR - "Ground Glass" infil, bilat sym dist
fine reticulonodular pattern on outer margins of consol
NO adenopathy, NO effusion
Tx w inhaled Pentamadine can shift pattern to upper
Pneumatoceles & Pneumothorax in assoc pathognomonic
CT - mult thin walled Air Cysts, Ground Glass pattern
Tx - pentamadine or bactrim, long term difficult & recurrent
should improve within 5d & clear within 10 days initially
steroids help, may scar but no honeycomb
DDx - TB, has adenopathy in 90%, eff in 25%, coarse retic pattern
miliary TB can sim PCP

Cryptococcus Neoformans - budding encapsulated yeast
usually disseminated in retic nodular pattern
Adenopathy & plueral eff assoc, 90% w concomitant meningitis

Coccidiomycosis & Histoplasmosis - prevelance by region
become disseminated in HIV, often N CXR
nodules - cavitate due to ischemic effect, adenopathy rare
3. Mycobacterium - strong assoc w AIDS
TB - 90% of present cases assoc w HIV, Curable
Follows N pattern in early Dz, coarse reticulonodular infil
Adenopathy in 90%, effusion in 25%
nodules do NOT cavitate
Mycobacterium Avium Complex - occurs in late AIDS, near terminal
Disseminated to GI, Blood & RES, Huge mediastinal nodes
No granulomas or sig tissue destruction
pulmonary Dz is least destructive aspect
Note - now effecting immune competent young women as well

4. Bacteria - manifest as early signs of HIV
S. Pneumonia & H. Influenza mainly, often multilobular, diss
S. Aureus, Rhodococcus equi & Nocardia also

5. Malignancy
Kaposi's Sarcoma - Lymphoproliferative, follows lymphatics
95% occurs in homosexual men, all w CMV, incidence decreasing
Pulm involvement always assoc w skin, often end-stage
CXR - poorly defined coalescent nodules
50% assoc w eff & thick linear opacities
should improve within 2-3wks after Tx
DDx - lymphoma or infection take up gallium
KS does NOT take up Gallium but does take up thallium
Non-Hodgkin's Lymphoma - Aggresive muliclonal B-cell type assoc w EBV
CXR - Sharply marginated Pulm nodules usual
very aggressive, can double in days, rapid response intitillialy
95% extranodal, dead in 6mo
Lymphocytic Interstitial Pneumonitis - Lymphoproliferative Dz
Exclusive in children, often presenting problem
Does not have malig transformation as in usual LIP
CD-4/CD-8 ratio reversed, CD-8 releases cytokines
lymphocytes, plasma cells & histiocytes enter interstitium
CXR - LOWER lobe reticulonodular infil, no rxn to Abx
Pseudolymphoma - focal form of LIP

INHALATIONAL DISEASES
Terminal Bronchiole is site of fallout for dust particles
damage occurs at this level

1. Silicosis - Asym for first 10-15yrs of exposure, UPPER lobes
fibers deposited in nodules, fibrosis surrounds
Nodules break up alveolar walls creating free air space
CXR - "ground glass" to Miliary to macronodule progression
Egg Shell calc of local nodes where silica deposited
Complicated Silicosis - Dx of silicosis w any nodule >1cm
Conglomerate masses created by nodules pulled in by fib
Discoid shaped w thin portion seen on lat views
Progressively retract towards hilum, NO cavitation, NOT premalig
TB - Much higher occ, overload of granulomatous response
most freq cause of cavitation
Silicoproteinosis - Overwhelming exposure, alveolar conso
progress to ARDS, cuboidal epi lining if survive

Coal Workers Pneumoconiosis - mixed w silica in all cases
Coal Macules - Unit Pathologic Lesion, stellate black nodules
differ from collagenous nodules characteristic of silica
progressive massive fibrosis, calc is due to silica component

Caplan's Syndrome - Combined Rheumatoid Nodules & silica
Lung hyperreacts to any foriegn dust
Nodules progress & regress like typical Rheumatoid nod

2. Organic Dusts - due to immunologic Mechanisms
Asthma & aspergilla - Tracheobronchial Hypersensitivity
Extrinsic Allergic Alveolitis - Farmer's Lung
Alveolar Hypersensitivity II' to spores
main injury is at repiratory bronchiole, extends to interstitium
Acute phase - Diffuse Mid & Lower lobe alveolar Edema
Granulomatous Rxn progresses to pulm fibrosis
Nodular patterns w NO adenopathy

3. Inert Dusts - Nonfibrogenic, dense enough to create CXR findings
Siderosis - inhalation of iron or iron oxide, no significant fibrosis
"looks bad, feels good" - mult nodules but no fibrosis
Deposits occur at Jxn of conducting & resp bronchioles
Like silicosis it takes 10-15yrs exposure before CXR changes seen
4. Asbestosis - 90% have plueral involvement w variable parenchymal
Pathology - Mg+ silicate forms silic acid w lung moisture
extensive alveolar wall rxn, FB giant cells seen
talc also contains Mg+ silicate
Plueral Plaque - hyalinized collagen in parietal pluera
#1 manifestation, 10% by 20yrs, 50% by 40yrs
occurs from ribs 7-10 along diaphragm, mediast & rib contours
Spares costophrenic angle & apices, NOT viceral like TB & hemothorax
Diffuse Pleural Thickening - when it extends over >4 interspaces
Pleural Calc - linear parallel to diaph, pathog, 40%
Irregular Pulmonary Densities - Lower lobe dist, fibrotic retic pattern
Not rounded like silicosis & coal
Round Atelectasis - Folded airless lung adhered to pluera
"Comet Tail" of vessels curling out of it
Mesothelioma - 20-40yr latent period
NO assoc w smoking, NO dose relation
freq assoc w plueral eff, Viscous due to Hyaluronic Acid
Adenocarcinoma - Most common form of Ca in asbestosis pt's
Inc risk w inc dose, 90x inc risk w smoking

5. Berylium - Granulomatous Dust, creates systemic disease
usually enters thru lungs but can enter thru skin
Cell mediated granulomatous Rxn forms Ag-Ab complexes
Type III immune complex Dz
CXR - Fibronodular infiltrate w hilar & mediast adenopath
DDx Sarcoidosis

6. Toxic Chemicals & Gasses - severity determined by solubility
Chlorine - very soluble, edema & obs of airway asphyxiates
Silo Fillers Dz - Nitrogen dioxide from organic decomp
Chemical pneumonitis within 2hrs, latent for 2-4wks
atel & nodular densities clear initially

GRANULOMATOSIS
Necrosis is key to DDx from Sarcoid

1. Wegner's Granulomatosis - Classic type w Triad of Sx
Demographics - slight male pred, 30-40yrs, rare in child
Pathology - transmural infil of vessel walls w inflam cells
necrotizing granulomatous inflam of arteris & veins
Clinical - triad rare, #1 presentation severe sinusitis
Pulmonary involvement in almost all eventually
Necrotizing glomerulonephritis leading to renal insuff
2 must be present for Dx, also eye, skin, nervous, DJD
Pulmonary Dz - mult nodules or masses of variable size & dist
Parenchymal consol in patchy pattern or reticulonodular
Rare solitary nodule, eff, adenopathy & hem
CT - Angiocentric lesions like mets

2. Lymphoid Granulomatosis - angiodestructive & lymphoreticular
involves primarily the lungs, probably a low grade lymphoma
30-60y/o, rapid progression of cellular lymphocyte infil
Reticulonodular w rapid changes, waxing & waning of coarse
Nodules & masses w necrosis & cavitation
adenopathy or splenomegaly indicates likely lymphoma

3. Necrotizing Ganulomatosis - sim to sarcoid but extensive nec
More striking vasculitis, extensive necrosis, rare adenopathy
4:1 female w wide age range, I' lung involvement, Benign course

4. Bronchocentric Granulomatosis - most in young male asthmatics
Caseous necrosis following small peripheral airways, bronchiolar
Mucosa replaced by palisading histiocyts w wall destruction
PERIPHERAL UPPER lobe dist, lobar or seg consol, atel, irreg nodules
Linear opacities of mucoid impaction, Bronchiectasis

5. Eosinophilic Granuloma - Langerhan cell infil of lung parench
90% assoc w smoking in mid age pt's, Adenopathy in kids, pneumothroax
Sx variable, no correlation w CXR, NO peripheral eosinophilia
CXR - Peripheral 3-5mm nodules are vasc & homogeneous early
Cavitate into nodular cysts - "Cyst & nodule" pattern, no vol loss
May resolve or honeycomb, 20% get pneumothorax, 10% assoc bone
Not assoc w Eosinophilic Pneumonia - see section on diffuse consolidation

6. Chronic Granulomatous Dz of Childhood - Familial
Defective Leukocytes, can phagocytize but not kill bacteria
CXR - hilar adenopathy & recurrent pneumonia, may abcess

SARCOIDOSIS
Demographics - 10x higher in blacks w 20-30y/o female pred
Rare in children but has white male pred, unkown etiology

Pathology - T-cell infil into pulm interstium
granulomas then form, NO NECROSIS, nodes become involved
Then either resolves or progresses to fibrosis
Dx of exclusion by path, R/O infectious or vasculopathy

Clinical - 50% asym, dry cough, dyspnea, 5% eye, 30% skin
Prognosis - PFT's best, CXR does not predict outcome
Lofgren Syndrome - classic triad of Sx, pathog, NO Bx needed
Bilat hilar nodes, erethyma nodosum & Uveits, good prognosis
>95% of pediatric pts symptomatic
Lupus Pernio - skin lesion in older blacks, bad prognosis
60% have elevated ACE due to macrophage activity
Lymphocytopenia due to sequetration in lungs, prone to Cryptococcus
Hypercalcemia - macrophage are extrarenal sources of vit D
Extractable Nuclear Antibody - ENA, specific for SLE
other labs like antinuclear Ab also seen w dermatomyositis etc

Staging - Stage 0 normal chest, 10% present this way
Stage 1 - mediastinal/hilar adenopathy, 50% presenting
Stage 2 - Adenopathy + infiltrates, 25% presenting
only 3% unilat, all progress to bilat, must Bx
eggshell calc poss but rare, 20% involve ant & subcarinal nodes
Stage 3 - Infiltrates alone, 15% presenting
Stage 4 - Fibrosis & Cystic changes, 20% progress to this
initial stage & steroid response do not predict who will progress
Bronchial Lavage can assist in predicting course of Dz
>28% lymphocytes indicates high intensity & better prognosis

Parenchymal Dz - 60% overall, adenopathy dec as this worsens
Fine nodular initially, diffuse, bilat & symetrical, can wax & wane
Reticulonodular w progression to Acinar rossets
DDx - Goodpastures, hem or mets, check age & adenopathy
Some mets do create casseating adenopathy, Bx lesion
Solitary Nodule rare, must Bx to R/O mass even if known sarc
CT - Ground Glass Opacities, nodules in bronchovasc dist
Fibrosis progresses w dist around bronci
Fibrosis localizes to UPPER lungs, Subplueral Bullae freq
Mycetoma - develops in 50% w cavatating Dz, steroids
Plueral involvement freq but NO effusion evident by CXR

OBSTRUCTIVE AIRWAY DISEASE
1. Emphysema
Centrilobar - #1, destruction to 1st & 2nd order resp bronchiols
sparing of the peripheral acinar alveoli, UPPER lobe dist
"Smoker's lung", assoc w chronic bronchitis & mucous prod
CXR - shows "prominent markings", Pulm HTN
Hyperinflation is NOT a major component
Panacinar - destruction of term bronchiol & alveoli
uniformly distributed thru the lung, can be LOWER dist
may destroy lower dist capillaries, redist vasc to upper
type assoc w Alpha-1-antitrypsin def
Paraseptal - involves the acinar periphery sparing cent acinus
usually SUBPLUERAL adj to intralobular septa
usual origin of giant bullae, usually not clinically sig
CXR - inc radiolucency, can be bilat, mult or isolated
Blebs, bullae, pneumatoceles & pneumothorax
bowing of sternum & wide retrosternal clear space
diaph flattened & serrated, small vertical heart if no heart Dz
Prominent cent pulm arteries, "Pruned Tree"
Irreg vasc distribution, can cause irreg dist of edema
Cor Pulmonale - late development
CT - sensitive for early detection of dec vasc & bullae
Nucs - Xe133 retained, matched VQ defect

Alpha-1-Antitrypsin Deficiency - Auto rec, chrom 14, presents at 40yrs
Panacinar Emphysema - develops in heterozygous ONLY w smoking
Homozygous develop it in 50%, liver cirrhosis & I' Ca in 25%
Hyperinflation w no lucency in early stages, LOWER lobes later
Straightening of pulm vasc, overall deminished vascularity
Hilar enlargement late due to pulm HTN

2. Bronchiectasis - can be infectious, congenital, obstructive, chemical or fibrotic
Infectious - inflam of bronch walls cause them to dilate
findings - basilar, first cylindrical then saccular, AF levels
Ring Shadows - abn dilated bronchi near hila & apex
signs of air trapping w dec vasc & flat diaph
Agammaglobulinemia - assoc w recur bac infection
Does not affect the diameter of the trachea
TB & Histo - can be a cause and combine cysts w cav
look for assoc loss of vol and apical plueral rxn
Allergic Bronchopulmonary Aspergillosis - can cause
assoc w asthmatic pts, spares dist bronchi
elev preciptin levels confirm aspergilla
Swyer-James or Macleod's Syn - Bronchiolitis obliterans
follows viral pneumonia, esp adenoviral bronchiolitis as infant
diffuse fibrosis of bronchiols causes air trapping
tends to hyperinflate alveoli & compress, NO wall destruction
severe unilat & patchy hyperinflation, "Pruned Tree"
effected lung N or small w inspiration, traps air w expiration
small vessels on affected side, contralat hyperperfusion

Congenital Bronchiectasis
Cystic Fibrosis - freq cause of Cystic Bronchiectasis, auto rec
#1 lethal genetically transmitted Dz of white children
Occurs in 1:2000 northern europeans, 5% carry gene
Exocrine dysfxn, defective chloride transport at cell mem
elev chloride & sodium in sweat
Mucopurulent plugging, dest of bronchial epi
CXR - UPPER lobe dist bronchiectasis, hyperinflation
freq enlargement of hilar nodes & pulm arteries
parapneumonic fluid poss, effusions overall not common
Kartagener Syndrome - immotile cilia syndrome, Bronchiectasis results
Situs inversus in 50%, poss due to lack of ciliary motion in embryo
assoc w sinusitus, Dextrocardia & strerility in males
Transposition to the great vessels & Double Outlet R Vent assoc
Bronchial Atresia and Williams-Campbell syn - structural defects

Obstructive Bronchiectasis - neoplasm, inflammatroy nodes, FB
Chemical Bronchiectasis - Aspiration or inhalation of toxic materials

MISCELLANEOUS

AMIODARONE TOXICITY
10% recieving drug, appears 1-4mo P initiation
most recieve >400mg/d, dyspnea, cough, anorexia present
focal alveolar opacities #1 presentation
also accumulates in liver lysosomes
iodine content makes liver appear dense


GOODPASTURE'S DZ
Hemoptysis, hematuria, Dx w renal Bx
Cytotoxic antibody mediated immune rxn
alveolar & glomerular basement mem damage by Ab
Most common in young males, glomerulonephritis alone in old female
95% present w cough & hemoptysis, renal Sx are usual cause of death
CXR - Diffuse patchy & acinar consolidation, whiteout poss
bilat coalescent densities, mid to lower distribution
Can resolve rapidly, resolve to retic pattern in 2 days
complete clearance in 2wks unless recurrent, can honeycomb
Dx - Immunoflorescent Ab to BM, Tx w steroids
NO necrosis present on path as in Wegener's Vasculitis


PULMONARY SEQUESTRATION
nonfunctioning, forgut anomaly, multiple fluid filled cysts
usually no comm to bronchi so infection rare
infection is the main cause of presentation though
60% assoc w other congenital anomalies - diaphragmatic hernia #1
freq coexistence w CAM also

Intralobar - 75%, within parenchyma, does NOT have it's own pluera
60% in L posterior base, 2:1 male, 10% assoc w congenital anomalies
Arterial supply from thoracic Aorta, drains to pulm veins
Left to Left shunt causes resp distress & cyanosis in neonate
Present in adulthood - 50% by 20yrs, cough, infection, hemoptysis

Extralobar - has its own complete pleura, no collateral drift, may drain
Present in neonates - 60% by 6mo, intrauterin poss, very echogenic
50% assoc w congenital anomalie, diaph hernia, TAPVR, renal
75% in L base, mid mediast or infradiaphragmatic, 8:1 male
Arterial supply much more variable, sm aortic branches or pulmonary

COLLAGEN VASCULAR DISEASE OF THE LUNG
usually occur in late stage, all have LOWER lober predom
all have freq plueral involved if parenchyma involved
Restrictive Lung Dz - decr pulm compliance but NO effect on FEV-1

1. Rheumatoid Lung - restrictive, diaph elev bilat
Unilat Pleural & Pericardial effusion are #1 presentation
Exudate w lymphocytes & possible empyema
may precede joint changes
PFT's show restrictive change before CXR change
Patchy Alveolar Infil - early fibrinous exudate
Fine Retic Nodular - lymphocytic infil, mimic miliary TB
cellular infil gradually replaced by fibrosis
Rheumatoid Necrobiotic Nodules - rare, assoc w advanced Dz
wax & wane w bone Dz, freq cavitation & fistulas
Caplan's Syndrome - rheumatoid nodules & pneumoconiosis

2. Scleroderma - similar radiologic progression
Fine Reticular pattern in LOWER lobes, assoc w cor pulmonale
thickened alveolar walls replaced by fibrosis, small cysts
late stages resemble Hamman-Rich pulmonary fibrosis
Primary vasculitis can also occur
inc incidence of pneumonia & adenoca
Pseudosacculations on antimesenteric side of sm bowel
LOOK for air filled esophagus left of the trachea

3. SLE - most likely to have pulmonary involvement, 50%
Ab complex deposits in alveolar walls
nonspecific usual interstitial pneumonitis, volume loss
freq plueral effusion, responds to steroids
Libman-Sacks Endocarditis - most distinctive cardiac lesion in SLE
No sig effect on valves, CHF rare, more severe w RA
most lung changes are not from lupus itself
atelectasis from pleurisy #1, infection #2 (nocardia)
Bilat sm lungs w elevated diaph, rarely fibrose
50% have nodes enlarged but very rare to involve hilar nodes
10% of cases are drug induced, less Renal & CNS involvement

4. Polymyositis - diffuse striated muscle Dz, effects upper esoph
Aspiration frequently results, patchy basilar opacities seen
interstitial Dz also possible but rare 5%
diaphragmatic weakness can cause resp failure, rare 5%
Dermatomyositis - when patchy red skin lesions are also present

SJOGREN'S
Chronic systemic inflam Dz assoc w Dry Mucous Membranes
Primary Dz occurs as recurren parotiditis in children
Secondary Dz assoc w Con Tiss Dz esp Rheumatoid Arthritis
Lymphocytic Interstitial Pneumonitis, pseudolymphoma
CXR - reticulonodular or patchy consol II' to dry resp epi

RADIATION INJURY
always sharply defined by port
rule of 4's - none if <4000rad, none if <4wks, greatest at 4mo

1. Acute Phase - lasts approx 6mo, blurred N vasc markings
Symptomatic radiation pneumonitis presents by 3-6mo
capillary obs w platlets & fibrin, endothelial damage
alveolar septa thicken w edema & intimal prolif
hyaline membranes in alveolar spaces
Plueral & Pericardial Effusion in 10%, Thickening more common

2. Late Phase - lasts an additional 12mo
alveolar walls show dense fibrosis, reduce capillaries.

NEONATAL CHEST
Embryonic Period - <6wk, ant pouch from foregut
bronchi & their branches differentiate
Pseudoglandular Period - 6-16wks, All major elements formed
airways remain blind ending tubules
Canalicular Period - 16-28wks, vascularization of lungs
resp bronchiols & term sacs develop, resp now poss
Saccular Period - 28-36wks, thinning or epi, prolif of caps
Surfactant begins to be formed
Alveolar Period - 36 wks on, terminal sacs to alveolar ducts
Mature alveoli do not exist until P birth

1. Hyaline Membrane Dz - Surfactant def II' to <36wks or DM in mom
"Hepatization" of lung, membranes line bronchioles
Alveoli necrotic, edematous & fill w fibrin
CXR - diffuse bilat granular opacities, "Rosetts" air bronchs
LOW lung vol, all other processes are hyperinflated
NO plueral eff, think of something else if present
May appear N if to early to even have alveoli that fill
term bronchiols simply dilate w nothing in acini
Glucocorticoids given to mother may hasten surfactant dev
Surfactant by ET critical to good outcome
Focal Hem in 1-2%, patent Ductus, germ matrix hem, pneumo

2. Bronchopulmonary Dysplasia - can develop even w/o hyalin Dz
Oxygen toxicity & Barotrauma cause acinar nec & fibrosis
Acini which develop later hyperinflate giving "cystic" app
surrounded by fibrous remenants of earlier damaged acini
Clinical Criteria - >3d on vent, >28d or resp distress on O2
CXR - prog from granularity to fibrotic, "strands & bubbles"
Late stage may have N app

3. PALM - Premature Infants w Accelerated Lung Maturity
Surfactant sys accelerated by stress or glucocorticoid Tx
CXR - can be slightly hazy but not true HMD

4. Transient Tachypnea of the Newborn - Retained Fetal Lung Fluid
Assoc w C-sec, precipitous delivery & maternal Diabetes
Interstitial edema pattern w Hyperinflation
Rapid clearing, 30% out bronchi, 30% lymphatic & 40% out caps
often no F/U if clinical correlates

5. Meconium Aspiration - 6% of mec stained infants, (33% of all)
Meconium seen below vocal cords, 5% die
Debris plugs airways, airtrapping leads to air leaks in 40%
Pleural Eff in 10%, PDA, poss progression to BPD

6. Neonatal Pneumonia - Diffuse granularity may mimic HMD
60% assoc w eff, B-Strep, HSV, CMV etc

7. Pulmonary Interstitial Emphysema - Air in intratubular septa
Acute Phase - Compresses blood vessels, Air migrates to surf
CXR - meandering cent tubular & periph cystic luciencies
Pneumothroax if one of the peripheral cysts ruptures
Chronic - >1wk, fibrous cyst wall localized or diffuse
may require resection
Pneumopericardium, venous air embolism etc

8. Congenital Lobar Emphysema - 40% occur in L Upper Lobe, 35% RML
1/3 present at birth, most present before 4mo, 3:1 male
Etiology - dysplasia or deficiency of bronchial cartilage
obs, inflam & or mucous, overinflation from ET
compression from PDA, aberrant L pulm art or dilated pulm art
Alveoli can inc in either number or size or both
CXR - hazy masslike opacity due to slow clearing of fluid (1-14 days)
hyperlucent expanded lobe which compresses adj structures

9. Pulmonary Lymphangiectasia - abn lung development at 14-20wks
Tortuous lymph channels, thick interlobular septa & supleural cysts
Present w respiratory distress within a few hours
assoc w TAPVR & hypoplastic L heart (ascending aortic atresia)

DDx for Neonatal Chest Dz
Low Lung Vol - HMD only, Mec asp causes plugging
Plueral eff - Pneumonia or Mec asp
never seen w HMD
Pneumothroax - Mec asp, HMD, normal newborn
never seen w pneumonia
White Out in HMD babe - PDA, Pneumonia, Pulm Hem, Neurogenic

CHEST WALL LESIONS
the incomplete border sign, always consider artifact

Skin Lesions - Nipples, moles

Soft Tissue Tumors - benign ones will not destroy rib
Lipomas - the most common chest wall lesion
either subQ or intrathoracic
CT confirms fat density, -10HU
Desmoid Tumor - benign, scar like, insidious growth
Muscle tumors, fibromas
Neural tumors - schwannoma, neurofibroma & neuroblastoma
Lymphoma - seen only in advanced stages
Askin Tumor - rare, arise from intercostal nerve in young females
neuroectodermal small cell tumor, sim to neuroblastoma
assoc w bone destruction & effusion

Bone Tumors
Mets & Myeloma - #1 in adults, osseus destruction, lace rib
Chondrosarcoma - #1 primary, look for calc matrix
Freq in sternum, ring & arc calc of chondroid matrix
DDx - Hamartoma of parenchyma has sim ring & arc calc
Osteosarcoma & Fibrosarcoma
Ewings Sarcoma - child, 30% have rib involvement
Rhabdomyosarcoma & neuroblastoma also in kids
Fibrous Dysplasia - ribbon ribs
Hemangioma - causes "basket-weave" bone destruction

Trauma
Fx and Hematoma - don't miss a lytic lesion underlying!

Infection - Is the patient febrile?, consider w bone dest
Actinomycosis - an aggressive granulomatous infection
causes rib destruction, eff, mass, and fistulas, R lung>L
proteolytic enzymes elaborated, found in sulfur granules
craniofacial involvement more common than lung
aspergillosis, nocardiosis, and blastomycosis sim

PLEURAL MASSES
move with resp if not attached to chest wall

Solitary Pleural Density
Loculated pleural effusion - use ultrasound
prediliction for minor fissure, resorb spontaneously
CHF #1 cause, Hemmorhage or neoplasm
if recent pneumonia think empyema
Mesothelioma - usually benign if solitary, NO Asbestos
Localized Fibrous Mesothelioma - often w long pedicle
may be seen at different locations between films
80% arise from visceral pluera in base, local invasion poss
Rare pleural eff unlike malig type, clubbing freq
if medial only bx can diagnose
may arise from an interlobar fissure
No chestwal or pulm ext if early malig or benign
Hypertrophic Osteoarthropathy IS assoc
Neural tumor - schwannoma, neurofibroma
Lipoma

Multiple Pleural Densities - each >2cm
Loculated pleural effusion
Metastases - #1, especially adenoca and melanoma
Mesothelioma - Malignant, unilateral, asbestos related
no typical findings of pulmonary asbestosis assoc
May be assoc w peritoneal mesothelioma as well
freq plueral effusion, rare distant met
Plueral plaques - asbestos related
Splenosis - assoc with spleen and diaphragm trauma
Malignant thymoma

Subpleural Parenchymal Lung Densities - Shaggy borders
Infarct - irreg and wedge shaped
Carcinoma - Includes Pancoast's
Metastasis - Interstitial and usually smooth
often peripheral
Pseudotumor - Inflammatory
Rheumatoid nodule - may be lg w central cavitation
Nodules & effusion spontaneously appear & regress
Fibrosis & granulomas assoc, do not change
Does NOT correlate w severity of bone Dz
Round atelectasis - folded lung, curving vessels characteristic
can be caused by retracting pleural fibrosis, assoc w thick pluera

PLEURAL EFFUSIONS
Most start subpulmonic before spilling to sulcus
lat shift of dome, flow freely on lat decub views

With Large Cardiac Silhouette - R/O postpericardiotomy
Congestive heart failure - cephalization, septal lines
88% bilat, 10% to Rt side, less to left due to ventricular motion
Fluid has <3g/ml of protien
Pulmonary Embolism - Lg Rt heart, Serosanguinous
SOB, Hemoptysis, friction rub, dec PO2, DVT
Myo or pericarditis - Causes pleuritis
from infx: Viral, TB, Rheumatic fever
Dressler Syndrome - Late Post MI syndrome due to autoimmune rxn
2-3wks post - fever, pneumonitis, pleural & pericardial effusion
effusion is not seen in immediate post MI syndrome
Post-pericardiotomy Syndrome - follows 2wks P heart surg
more common than post-op infection for pleural effusion
Postoperative of any kind for Abd or chest, occur w 50% of abd surgery

Effusion assoc w Pulm Density - always consider PE
Neoplasm - Bronchogenic ca or lymphoma
Mets & mesothelioma
make up 50% of noncardiac effusions
Pneumonia with Empyema - trauma or infection
WBC and bugs in eff, not simple Parapneumonic eff
TB - Thorocentesis with culture or bronchoscopy for Dx
Glucose in effusion fluid rises P high glucose meal
Rheumatoid Dz - fluid does not have a rise in glucose level, R>L
SLE - occurs in up to 75%

Dec Colloid Oncotic Pressure - Assoc w Cirrhosis & ascites, 70% R side
Hepatic Hydrothorax - assoc P cirrhosis & ascites, R>L
filters thru lymphatics or fibers also, No assoc infection

Meig's Syndrome - benign ovarian fibroma assoc w effusion
Ascites & plueral effusion resolves P resection, R>>L

Trauma - look for assoc rib Fx etc
Chylous Effusion - penetrating trauma & surg to L upper lobe #1 cause
R side if trauma form T5-7, L side if upper portion damaged
Boerhaave's Syn - almost always L sided eff

Abd Mass, abcess or ascites - Elev Rt hemidiaph, free air

PLEURAL THICKENING
usually an organized eff, nonspecific
Watch for artifact or muscle fold

Trauma - Fibrothorax from organizing hematoma, #1 cause

Infection - Chronic Empyema, TB, Aspergilla Ball

Neoplasm - look for bone destruction etc.
bone scan has inc sensitivity
Compare old films, change means neoplasm or inf
Mets, Mesothelioma, Pancoast's
Leukemia in a child

Inhalation Dz
asbetosis - lat or diaphragmatic
parietal pleural thickening instead of visceral
fibrosis can progress to pseudotumors
Mesothelioma or I' parenchymal Ca must be considered
talcosis - used to cut cocaine

Connective Tissue Dz - Rheumatoid & Sarcoid freq manifestation

PNEUMOTHORAX
Trauma - by far #1
Ventilator induced II' to interstitial air tracking to mediastinum
then ruptures to plueral space, NOT due to bleb rupture
interstitial air appears as mult branching irregular lucencies
mediastinum also comm w retroperitoneum via esoph hiatus
Eosinophilic Granuloma - assoc w spontaneous pneumothorax
Alveolar Proteinosis - often presents as pneumothroax & eff
Catamenial Pneumothorax - endometriosis causeing mult recurrent
always consider in a young women, monthly cycle of pneumothorax
Osteosarcoma - young person w met to lung
Lymphangiomyomatosis - also w pneumothroax & chylous eff

PLEURAL CALCIFICATION
frequently diagnostic

Infection - can still hold fluid if calcified
Empyema - organized, often involves fissures
TB - apical and asymetric diagnostic, esp with mult gran

Trauma
Healed hemothorax - look for old fx
contusion resolves without scar or thickening
Penetrating trauma leading to empyema

Inhalation Dz
Asbestosis - Multiple calc plaques <3-4cm diagnostic
esp if asym, lat and diaphragmatic
Talcosis - fibrogenic only with silicates

ELEVATED DIAPHRAGM
Unilateral significantly different from bilateral
Bilat due to poor insp, ie obesity or pain
Crura - tendenous insertions, R larger than L
azygous vein & throacic duct lie on the dorsal surface

Subpulmonic pleural eff - most common immitator of elev
apparent dome of diaph shifted lat, medial lung tethered
suspect other probs, get lat and decub views

Altered pulmonary volume
Atelectasis - usually from lower or middle
Postop vol loss - look for rib def and suture
Hypoplastic lung - sm hemithorax with sm pul artery #1Dx
Usually Rt side, assoc with aPVR and dextrocardia
Periph lung vasc is bronchial, irreg orientation
elev diaph and media shift not neccessary for Dx
Scimitar Syn - consider w hypoplastic R lung
Nerve Paralysis
Unilateral usually due to phrenic - paradoxical motion on fluoro
lat view best, sniff test
Lung tumor, Mediastinal mass, postop, idiopathic
Bilateral - neuromuscular disease
amyotropic lateral sclerosis, myasthenia gravis

Diaphragmatic abnormality
Hernia - Bochdalek (postlat) or Morgagni, check lat view
Traumatic rupture - look for AF levels on Lt
liver on Rt, look for fx, contusion, eff, etc
50% are missed on initial CXR
freq delay of herniation of abd contents, hrs to yrs
incarceration of herniated contents worst complication
Tumor - only if massive, no loss of motion
Eventration - may be large in infants
can have paradoxical motion on flouro
difficult to DDx from paralysis of diaph

Abdominal Dz
Subphrenic abcess - asoc with Lt eff, US diagnostic
Distended viscera
Chyliditi Syn - colon between diaph and liver
benign, would not explain an eff

SHIFT OF THE MEDIASTINUM
Severe asymetry in intrathoracic Pressure
Expiratory film and flouroscopy determine side of abn
Lat decub film if pt uncooperative

Decreased Lung Volume
Atelectasis - #1, look for elev diaph and crowded ribs
Sm mass can cause atelectasis
Hypoplastic lung - sm pulm art, brochial periph vessels
Postop - lobectomy

Increased Lung Volume - may herniate thru mediastinum
FB in Lg bronchus - #1 in kids, shift to normal side
Bronchogenic cyst - infants, single with ball valve
Cystic Adenomatoid Malformation - infants
Complex forgut anomaly, 3 types, see OB file
Congenital lobar emphysema - infants, usually upper lobe
no well defined walls as with cysts, flat diaph
Bullous emphysema
Interstitial emphysema - air follows arteries
causes diffuse coarse lines, due to vent
Swyer-James syn - bronchiolitis obliterans, rare
follows viral inf, sm airway obstruction
air trapping not always assoc
Interbronchial Adenoma - 80% central w assoc vasoconstriction
90% are carcinoids

Pleural Space Abnormalities
Tension Pneumothorax - collapsed lung may be late sign
lucency above heart and in azygoesoph recess
resembles herniation of an over-ex lung, flat diaph
Lg unilateral pleural eff - almost always assoc w shift
consider mediastinal fixation by a mass if not shifted
thoracentesis for Dx
Lg diaphragmatic hernias
Lg masses

Partial absence of the pericardium - heart shift only

WIDENING OF THE MEDIASTINUM
CT, MRI, and aortography for follow up

Technique error - lordotic or magnification

Vascular Structures
Tortuos or ectatic aorta
Aortic Dissection - CP, syncope, periph vasc obst
Debakey classification of dissection
type I - root to descending, 30%
Insufficiency often
type II ascending only, 20%
type III decending from SCA, 50%
Stanford type A - ascending & decending involved, 70%, surgical
type B - decending only, 30%, conservative management
Aortic Coarctation
Lt SVC - congenital

Trauma - hemorrhage #1, can also occur due to coagulopthy
creats smooth enlargement, plueral eff freq
Interstitial tracking poss, sim pulm edema
vascular tear or transection - esoph or trach dev poss
Aortagram if >8.5cm, paratrach line >5mm, apex cap
penetrating trauma
vertebral and sternal fx - does not exclude aortagram
Postop or Malpositioned CL
Chylomediastinum

Neoplasm - due to extensive nodal involvement
scarring may follow Rad tx or chemo, use PET to dif
Lymphoma or Sm Cell - most likely to infiltrate
loss of N tissue planes on CT, obs SVC or bronchi
Bronchogenic ca, Mets

Pneumomediastinum - alveolar rupture II' to inc P #1
dissects centrally, also w bronch or esoph rupture
Plueritic type pain assoc w event that caused P inc
Air along L heart border #1 finding, air fixed, NO AF levels
Pneumopericardium - limited by upper reflec of pericardium
II' to infection w assoc fluid levels
Mediastinitis Acute - II' to bacterial infection, traumatically introduced
Boerhaave's Syn - vert tear along posterolat wall, dist esoph
mortality 50%
penetrating inj, Iatrogenesis or extention of neck infection
Widened sup meniast in 60%, plueral eff in 50%
Dx w esophagram or CT
Mediastinal edema - allergy

Chronic Sclerosing Mediastinitis - Rare, usually II' to HISTO
Probable hypersensitivity to fungal antigen leaking from node
75% involve the SVC & assoc SVC occlusive syn
Obs central pulm veins most serious, mimics mitral stenosis
Lg calc lymph nodes often assoc, Bx to DDx from malig Granulomatous adenopathy - TB and coccidiomycosis
Mycobacterium avium intracellulare in AIDS

Lipomatosis - benign, 50% idiopathic
Cushings syn, corticosteroid tx, Obesity, Norm variant
smooth, prom epicardial fat pad, Trachea NOT displaced
Lobulation poss if fat deposits extensive

Multiple symmetric Lipomatosis - rare, trachea displaced
ant mediast, cardiophrenic angles & paraspinal spared

ANTERIOR MEDIASTINAL MASS
ant to trachea and post heart, the 4 "T" lesions
Obliterates the ant jxn line - V shaped confluence of ant lungs

Thymic lesions - sharply defined, rare calc, pt >40y/o
N thymus at maximum wt by puberty
may also have normal enargement following lymphoma Tx
MRI - abn determined by heterogenity, size & shape not signal

Thymic Hyperplasia - enlargement w N histology
#1 in children, response to stress, rarely causes resp distress
Seen in 60% of Myasthenia Gravis pts
only 15% have thymoma

Thymoma -#1 mass here, 50% of adults develop myasthenia gravis
does not compress against sternum: sulcus sign
Tumor classified by cell of origin
Lymphocytic, Epithelial or mixed
40-50y/o, 25% calc, 10% cystic
rare in children & never assoc w myasthenia gravis
25% are locally invasive to chest wall or drop mets to pluera
distal mets are very rare
CXR - detects the majority of masses, CT helpful

Thymic carcinoid - Neural crest origin, Kulchitsky cells
25% develop cushings and MEN, II' to coritcotropin sec
Aggressive but usually Dx early due to cushings
Rarely develop carcinoid syndrome

Thymic cyst - epi lining, thymic tissue in wall
Assoc w treated Hodgkins Dz, P thoracotomy or congen
DDx - Cystic deg of thymoma, lymphoma or germ cell

Thymolipoma - Rare, benign lipoid & thymic tissue mix
May envelop heart & diaph, asym, resection currative
CT - readily defines lg fatty components

Thymic Carcinoma - epi cells form squamous ca, lung met
local invasion seen at time of Dx

Thymic Lymphoma - seen in 50% of sclerosing Hodgkin's
Other enlarged nodes key to Dx
DiGeorge Syn - Thymic & parathyroid aplasia
3rd & 4th pharyngeal pouch deformity, thyroid hypoplasia also
Susceptable to infection & hypoparathyroid
low set ears, mandible deformity & congenital heart Dz

Germ Cell Tumors - Cell rests from migration to gonads
Histo identical to gonadal ca, must exclude gonadal I'
assoc w retroperitoneal nodes
Softer, tend to compress, no sulcus

Teratoma - #1 benign germ cell neoplasm, usually cystic, F>M
Solid usually malignant, almost exclusivly male
90% ant mediast, 10% post, sim distribution as thymoma
Usually smooth & soft, lobulation indicates malig
Calc in 50%, nonspecific unless a tooth seen
#2 pediatric ant mediast mass after lymphoma

Dermoid cyst - may see a fat fluid line on CT, rim calc
epidermoid if squam lined, dermal if hair & glands

Seminoma - #1 malig, seen primarily in young men
CT shows lobulations w Hem, Nec & Calc

Choriocarcinoma - also malig & male, elev B-HCG levels
gynecomastia freq presenting sx

Endodermal Sinus Tumor - yolk sac, secrete a-fetoprotien
Seen primarily in young men

Thyroid - Actually an INLET lesion, common in adults
Usually an incidental CXR finding, displaces trachea
Dyspnea from tracheal deviation is rare
Goiter - Freq course clumped calc, Nuc study should be 1st
High CT attenuation due to Iodine content
Enhance intense & prolonged, >25HU due to hypervasc
Adenoma - also parathyroid
Carcinoma - see "thyroid" section of "neuro" file
Parathyroid Rests - occur in 2%, often within thymus
May become symptomatic if microadenoma assoc

Lymph Node Enlargement
Hodgkins Lymphoma - #1 I' mediast mass in adults & kids
Presentation - bilat hilar, paratracheal & int mammary nodes
Spreads contiguosly, no post involvement
Never calc if untreated, post Tx calc good prognosis
CXR - well defined lobulated mass on PA, indistinct on lat
<10% has lung parenchymal involvement
30% have assoc plueral eff, no direct plueral invasion
CT shows freq residual mass P Tx, may recur in 6-12mo
duel age dist in young and very old
Linear & irregular nodular densities assoc in lungs

NHL - only 40% involves mediastinum, rarly isolated
more likely to have multifocal spread, post involved

Benign hyperplasia
Angioblastic lymphoid adenopathy
Sarcoidosis - much less common than Hodgkins in ant mediast

Cardiovascular - Epicardial fat pad
Aneurysm of ascending aorta, or sinus of valsalva
Dilated SVC, False aneurysm of com carotid - trauma
Pericardial cyst, Cardiac tumor
Rt Cardiophrenic Angle Mass - fat, aneurysm, diaph
#1 location for pericardial cyst

Mesenchymal Tumors
Lipoma or lipomatosis - uniform w attenuation of -50HU
Bronchogenic cyst, Hemangiomas
Neural tumors & Paraganglioma - pheo and chemodectoma
Morgagni hernia, Leiomyomas, fibromas
Sternal ca or mets

Cystic Hygroma - Lymphangioma, cysts in the fetal neck
congenital lymph blockage, assoc with trisomy, XO

MIDDLE MEDIASTINAL MASS - 4 main types, 90% malig
Lymphadenopathy #1, Duplication Cysts, Tumors & Vascular

Lymph Node Enlargement - most are malignant
Azygos, subcarinal ,ductus, and paratracheal nodes here
form elongated lobular masses rather than spherical
Distort the lung mediastinal interface, Calc possible

Neoplastic Adenopathy - use CT for staging, calc rare
Mets - #1, usually from bronchogenic ca
Squamaous cell ca often causes central necrosis
sm cell ca can mimic lymphoma due to early med mets
Usually unilat, assoc w pulm or hilar abnormality
Paratrachial & AP window nodes #1, Bx before Tx
Hodgkin's - esp in ant and hilar nodes
Nodular Sclerosing 60%, Mixed celllularity 20%
Bilat but asym, Freq central necrosis
NHL - seen only as solitary nodes, Systemic Dz
Luekemia - 25% in late stages, Usually T-cell variant
Kaposi's Sarcoma - hypervasc, brightly enhance

Inflammatory Adenopathy - look for assoc infil or abcess
Sarcoid - usually hilar, garlands triad, EGGSHELL calc
Adenopathy occurs in 90% at some stage
CT show nodes do not coalesce as in lymphoma
TB - Caseating gran cause fibrosis & Central nodal calc
also freq cause of central necrosis
Histo - nodes large, calc often & central
Coccidio and Blastomycosis - mimic TB
endemic in desert southwest
Viral - can cause nodes in peds, assoc infil like TB
mononucleosis has enlarged spleen, no infil
AIDS - sm nodes from reactive hyperplasia
Bacteria - rare, anthrhax, bubonic plague, tularemia
Castleman's Dz - Angiofollicular lymph node hyperplasia
N nodal architecture replaced w mult germinal centers
Highly vascular, enhance intensly on CT, Tx w resec
Connective Tissue Dz - rheumatoid and lupus

Inhalational Dz Adenopathy
Coal pneumoconiosis and Silicosis - assoc w pulm DZ
silica picked up by macrophage and taken to nodes
granulomatous rxn, fibrosis, EGGSHELL calc
Berylliosis - granulomatis rxn sim to sarcoid, need exposure Hx
Primary Tumors
Lymphoma
Tracheal Ca - Stridor and hemoptysis freq presenting c/o
Bronchogenic Ca
Esophageal Tumor - dysphagia before mass effect
Begnign - leiomyoma, can be lg before obstructing
Malignant - Ca, leiomyosarcoma
thick post paratrach stripe on lat, esoph AF level
Mesothelioma

Vascular Lesions
Aneurysms - seen in all parts of the mediast
Distended SVC or Azygos - use fluoro to see
change in size w position or valsalva manuever
Left Superior Intercostal Vein - can appear prom when dilated
creates a "Nipple" on the aortic knob, assoc w tricuspid Dz
Hematoma
Angiosarcoma of PA
Lt SVC, Aberrant Rt Subclavian Art, Rt Aortic Arch

Esophogeal - Hiatal hernia, Esophogeal Diverticulum, Achalasia

Duplication Cysts - rare, but this is #1 location
often homogeneous dense fluid, use MRI to diff
CT does not reliably differentiate cystic from solid

Brochogenic cyst - #1 congenital cyst, from ventral foregut
90% at carina, may extend to R side, asym young person
compression of airway more likely in child, resp distress
Histo - lined w resp columnar epi, mucous glands, CARTILAGE
CT - just slightlly denser than water, 0-10HU
always smooth & homogeneous, spherical & unilocular
NO enhancement, AF level poss but comm to bronchi rare
Parenchymal cysts comm more freq, more likely to be infected
DDx - other cysts, use histo to eval lining, inflam may prevent Dx
Adenopathy - enhances heterogeneously, more dense initially

Enteric cyst - from dorsal foregut, gastric epithelium
occur in sim location to mediastinal bronchogenic cyst
Pericardial Cyst - R ant cordiaphrenic angle, serous
Sequestration - complex mult cysts, 2/3 in lower lobes, most post

Inlet lesions - Thyroid, Cystic Hygroma (lymphangioma)

POSTERIOR MEDIASTINAL MASSES - 1cm behind vert body ant line
mophologic features combined w Hx usually give Dx
Obliterates the post jxn line - confluence of post lungs

Neural Lesions
homogeneous, dense, evenly dist speck calc in 25%
Benign - errode bone, spread neuroforamina
Malignant - destroy bone, spread ribs

Nerve root tumors - 80% ROUND, more lat with med sulcus
Spindle cell histology, form from intercostal nerves, 10% dumbbell
Schwannoma - #1, no nerve cells unless malig, 20-30y/o
Neurofibroma - #2, both schwann and nerve cells, 20-30y/o
30% have neurofibromatosis type I, rare w type II
some malig transformation, cafe-a-lait spots
Mult mediast masses esp in posterior apical region, pathognomonic
Scoliosis of LOWER thoracic vert freq
MRI - may show both intra & extra spinal components
High signal intensity on T2

Ganglion Tumors - sym gang origin, 80% VERTICALLY oriented
Very specific age distributions, more likely to calc
All produce catecholamines, metanepherines in urine
Neuroblastoma - malig, undiff round cells, <1 y/o
most from adrenal, 15% from mediastinum
Ganglioneuroblastoma - mixed, malig round cells
con tissue, and mature ganglion cells, 1-10y/o
Ganglioneuroma - benign, mature gang cells, 10-30y/o

Paragangliomas - aortic or aorticosym ganglia origin
Chemodectoma - nonfunctioning, exclusively in AP window
Pheochromocytoma - functioning, HTN & unrine metaneph
2% arise in mediast, most middle or ant

Lateral Meningocele - 85% assoc w Neurofibromatosis
Assoc w marked bone errosion & scoliosis
Only 10% assoc w Sx, may be multiple
Esophageal Lesions
Esophageal Carcinoma - The vast majority are Squamous
rarely asym if seen on CXR, Dysphagia & wt loss
Loss of azygoesophageal interface & widened mediast
Benign Esophageal Neoplasm - leiomyoma, fibroma & lipoma
involve lower 1/3, NO dil or obs, smooth mass on CT
Hiatal Hernia - gastric cardia in sliding type
Fundus or any abd structure in paraesophageal type
Pulsion Diverticuli - mucosal outpouching, AF level poss
Zenker's - post cervical, may project at inlet (killians dehisence)
Achalasia - causes dialtion, AF level freq
Scleroderma or any cause of dist stricture similar
Esophageal Varices - retrocardiac mass, assoc portal HTN

Duplication cysts - curvilinear calc freq, AF if comm
Enteric cysts - fluid filled w gastric epith lining
histo identical, present in child due to early sym
Neurenteric cyst - enteric cyst w comm to spinal canal
Assoc w congenital vert anomalies cephalad to mass
Hemivert, butterfly vert or ant spina bifida
Bronchogenic cysts -usually middle mediast near carina, asym adult
obliterates the Azygoesophageal recess line
Sequestration - 2/3 in lower lobes & post

Inflammation
Paraspinous abscess - TB, develops rapidly
vert end plate & disk destruction; Pott's, not always seen
Mediastinitis or Empyema
Lymphoid hyperplasia
Sarcoidosis - assoc w garlands triad

Vascular lesions - curvilinear calc in 50 y/o
Aneurysm of dec aorta - obl view can R/O sep mass
Extramedullary Hematopoesis - usually mult & bilat masses

Trauma - Aneurysm, Hematoma, Pseudomeningocele
Vert body Fx

Abdominal Origin Posterior Masses
Bochdalek's hernia - continous w contour of diaph
retroperitoneal fat and kidney most com, IVP for Dx
Pseudocyst - eff freq, correlate w clinical Hx
Retroperitoneal masses - teratomas, sarcomas that met
Other processes causing post mediat mass
Mets - look for bronchogenic primary
abd masses to post mediast via thoracic duct
Cervical processes also via lymphatics
Lymphoma - look for systemic sym, wt loss, low temp
assoc with hilar adenopathy
Mesenchmal tumors - fibroma, lipoma, leiomyoma
Hemangiomas
Thyroid tumors
Vertebral tumors - osteoblastoma, giant cell tumor, met
Lipoma or lipomatosis
Extramedullary hematopoesis - lg ribs, spenomegaly, Hx
Mass from extruded vert marrow poss w thalassemia
Psuedomass of newborn

HILAR ABNORMALITY
Inf Pulmonary Veins do not contribute significantly to hilar shadow
If a mass is distinct on PA it is ant or post, check lat
smooth = vascular, nodular = adenopathy, CT or MRI for DDx

Pulmonary HTN - N pressure 20/8, HTN if P>30mmHg
Enlarged Prox Pulm Arteries - Lt >18mm, Rt >16mm
peripheral vasculature decreased
Enlarged Rt vent fills retrosternal clear space
45 deg RAO will confirm, norm periph vasc excludes
Calc of prox pulm arteries rare but pathognomonic
Cor Pulmonale - end stage R heart failure, hypertrophy
Alveolar pO2 & acidosis determine pulmonary art resistance
No effect from epinepherine, contrast, nerve stimulation etc

Emphysema & Chronic Interstitial Dz - collapse of intralpulm vasc
#1 cause of Aquired PAH, Inc Vasc Resistance, Normal Wedge Pressure
Chest wall Deformity, diffuse plueral fibrosis
Fibrosis can develop from hypoxia - apnea, kyphosis
Schistosomiasis - can result in the classic "Pruned Tree" appearance

Primay Pulmonary Hypertention - Plexogenic Pulmonary Arteriopathy
Intimal fibrosis obliterates mid sized art, adj plexus forms collaterals
PAH & Cor Pulmonale result, N VQ scan, Normal Pulm Wedge Pres
Occurs only in young females, Simulates Microembolic Dz

Lt Sided Heart Failure - #1 cause of Rt side heart fail
dilated Rt upper lobe vein, Elevated Wedge Pressure
venous htn causes Edema which blurs hila
Mitral stenosis and CHF - cephalization, dilated seg artery
Changes of venous htn & edema early
Once PAH has developed these may be absent

PE - Hx of pleuritic cp, hemoptysis, thrombophlebitis
Tumor emboli - difficult to Dx, lung Bx

Eisenmienger Physiology - severe long standing L to R Shunt
VSD, ASD, ECD, PDA, truncus arteriosis, TOGV
High out put states have sim app - thyrotoxicosis etc
Medial arterioles eventually hypertrophy, INC resis

Atrial Myxoma
Idiopathic - Dx of exclusion
Unilateral Hilar Enlargement - sim to mid mediast DDx
Neoplasm - bronchogenic #1, early
Squamous cell - often presents this way
mass is central extention of endobronchial tumor
Sm Cell - bronchial submucosa & lymphatics involved
Adenoca & Large cell ca - rarely have hilar involve
peripheral presentation
lymphoma - rarely unilat
mets - abd masses to post mediast via thoracic duct
Cervical processes also via lymphatics

Inflammation - primary TB, fungus, viral, abcess
Concominate parenchymal Dz in immunecompentent pt
in child TB can be assumed, Bx adult to R/O ca
Bacterial - Tuleremia, G- abcess & bubonic plague
Viruses - Mononucleosis & measles pneumonia

Unilat Pulm Art Enlargment - Aneurysm, poststenotic dil

Bilateral Hilar Adenopathy
Sweetie, Please Lick My Huge Popsicle
Sarcoid - #1, 80% bilat & symetric, Bx to R/O ca
if eff involved sarcoid least likely, <3%
nodes may have punctate or eggshell calc, enhance
Primary TB - often unilateral
Lymphoma - Hodgkins more often bilat than NHL
Never see hodgkins in hila w/o ant mediast involve
Leukemia - 25% present w bilat hilar nodes, esp CLL
also assoc w central coarse infiltrates, 40% w effusion
Mets can be bilat but rarely symetric
Sm Cell & Melanoma #1
Histo or Bacterial can be bilat
Pneumoconiosis - Silicosis, EGGSHELL calc, may be unilat
sim sarcoidosis
Collagen vascular Dz - SLE, polyarteritis nodosa
Dilantin - Angioimmunoblastic Lymphadenopathy
rare cause of hilar nodes

Duplication cysts - unusual locations, Bx for Dx
Small hilum - almost always unilat
Resection or Atel of a portion of lung
Tet & Ebsteins anomaly cause bilat

TRACHEA AND CENTRAL BRONCHI
Congenital Abnormalities
Supernumary Bronchi - rudimentry pouches from R dist trachea
2cm prox to carina, contains all wall elements, pt usually asym
Bronchial Atresia - assoc lung is hypoinflated
Tracheoceles - Aquired Pressure diverticula II' to valsalva etc
occur exclusively in post portion of cervical outside of pressurized chest

Extrinsic lesions - tend to displace w/o narrowing
Intrathoracic goiter, Paratracheal lymph nodes
Aneurysmal aortic arch
Apical scarring - cicatrization causes traction deformity

Inflammatory Lesions
Wegener's Granulomatosis - nec gran inflam of trachea
assoc w upper airway & renal involvement
Cyclophosphamide tx early can prevent serious seqeula
Sarcoidosis - rare cause of narrowing
TB - bronchial or tracheal involvement
Aspergilla, candida, mucormycosis - immunecomp pts
Klebsiella - can cause tracheal scleroma (chronic gran Dz)
Aquired Diverticula - postinflammatory, flask shaped w narrow neck
follows drainage of puss from bronchial or tracheal mucus glands

Tracheal Neoplasms - 90% in adults, most are malignant
Squamous cell - 50%, 40+yrs, smokers, present w cough
within 3-4cm of carina, 50% extended at Dx
Adenoid Cystic ca - Cylindroma, from post tracheal salivary glands
40% of tracheal ca, occur at 20-40yrs
lobulated & eccentric usually post, >2cm malig, <2cm benign
Carcinoid - Kulchitsky neurosecreting cells, 3% get syn
occur at central bronchi, present w atelectasis & pneumonia II' to obs
"Iceberg" - sm intraluminal & lg extraluminal components
Good prognosis even w metastisis
Adenoca, lymphoma, Sm cell & mucoepidermoid
fibrosarc, chondrosarc & leiomyosarc also
Extention of laryngeal, bronogenic or thyroid ca
Mets - breast, kidney, colon & melanoma
Benign Tracheal Masses
Chondroma - from rings, well circ luminal mass, stipled calc
Fibromas - cessile or pedunculated
Papilloma - squamous cell origin, II' to human papiloma virus
Mult masses in kids of mothers w warts, regress by adults
Hemangioma - exclusive in kids
Granular Cell Myoblastoma - from neural elements, cervical #1
Pulmonary Hamartoma - Mixed pulm elements, 90% extrabronchial
cart, fiber, fat & mucous glands
Ectopic Thyroid or Thymus, Mucus plugs

Diffuse Tracheal Narrowing
Saber-Sheath Trachea - coronal dia 60% < sagital dia, inlet to carina
Tracheal wall uniformly thickened & calc
Assoc w COPD & chronic cough
Amyloidosis - Submucosal Deposits, focal irreg & calc
protien-polysaccarides seen w congo red on Bx
Tracheobronchopathia Osteochondroplastica - benign calc nodules
submucosal osseus & cartilage deposits, NO ulcers or tics
often involves entire trachea, not premalignant, 3:1 male >50yrs
Post membranous portion spared, Dx made w bronchoscopy
Relapsing Polychondritis - inflam of cart of ear, nose, trach
initialy complient & dilated, later fibroses and narrows
Early detection important, Steroid Tx can help, death otherwise
Post-intubation Tracheal Stenosis - Focal narrowing near thoracic inlet
gradual onset 2wks P and progress for months

Diffuse Tracheal Dilation
Mounier-Kuhn syndrome - Tracheobronchiomegaly, male <50y/o
Diverticuli cause a Sacculated appearance
Congenital defect of smooth musc & elastic components
Trachea >3cm, central bronchi collapse during coughing
CT - dilation of trachea & Bronchiectasis II' to recurrent infec
Tracheobronchomalacia - Aquired by bronchial injury
appearance & sx sim to tracheobronchomegaly
Ehler's-Danlos Syndrome - rare occurance in a rare Dz

TRACHEAL & BRONCHIAL INJURY
Tracheoesphageal Fistula - most due to trauma, Cough dyspnea & aspiration sx
mediastinitis when acute, no leakage if chronic II' to intubation
histoplasmosis, lye ingestion,
Freq assoc w aortic , rib & sternal injury
forceful compression against vert column usual mech
80% proximal main bronchi injury, 15% dist 2cm of trachea
Pneumothroax or pnuemomediast that does not respond to chest tube
lung remains collapsed against lat wall, "fallen lung"

ATELECTASIS - airlessness
overinflated contralat lung, med shift, diaph elev, cardiac rota
Juxtaphrenic peak - diaph pulled up, freq w Rt up atel
fissure displacement most specific
Rt lower lobe atel - maj fis becomes vis on PA

Obstructive Atelectasis
Neoplastic Obstruction of Lg airway
Bronchogenic ca - #1, often present as recurrent atel
look for signs of obst esp if abx only clear partialy
stage w CT for freq liver and adrenal mets
Bronchial carcinoid - from bronchial neurosecretory cel
Kulchitsky cell ca - class I&II carcinoid, III sm cel
Lymphoma - advanced or recurrent, Mets - rare

Inflammatory Obstruction of Lg airway
TB - endobronchial granuloma, bronchial stenosis
broncholiths - calc nodes that errode into bronchus
Sarcoidosis - obs rare, as in all hilar adenopathy

Wegener's Granulomatosis
FB - causes air trapping in child, adj compresive atel
ET or NG most common cause of FB in adults
Lg Lt atrium - as in mitral stenosis, look for ceph
comp Lt main and lower lobe bronchi

Mucus plugs in small airways
Asthma - bronchial wall thickening and plugging, atel only w extensive Dz
Pain - esp postop, subseg bands can occur, unkown etiol
Resp depressent drug, Cystic fibrosis, Inflammation
Bronchopneumonia, Bronchitis, Bronchiectasis
Passive Atelectasis - plueral space occ processes
Lung tends to collapse when pushed away from pluera
Pneumothorax - get exp film, watch for skin fold fakeout
Pleural eff, Diaph hernia, Plueral masses

Compressive Atelectasis - intrapulmonary occ problem
A form of Passive atel, Parenchymal Tumor etc
Extensive Interstitial Dz - sarcoid, lymphoma
usually more obstructive due to endobronch lesions
Mediastinal shift - Air trapping in adj lung

Adhesive Atelectasis - alveolar walls stick
Type II pneumatocytes damaged, dec surfactant prod
PE - loss of surfactant causes adhesion, no tis infarct
pneumoconstriction due to inc dead space
elev diaph, resembles subseg atel, eff common
Hyaline Mem Dz - resp distress syn, no surfactant
diff ground glass, coalesses to solid, air bronchs
IV hydrocarbon

Cicatrization Atelectasis - fibrosis and scar
look for assoc coarse reticular densities
TB and Histo - seg or lobar densities
Other types of pneumonitis - diffuse, bilat vol loss
Radiation - late stage, nonanatomic dist
Silicosis - more upper lobe, exposure Hx
Scleroderma - more lower lobe, other organs involved

SEGMENTAL AND LOBAR CONSOLIDATION
Water, Puss, Blood, Cells or Protien in order of acute to chronic
Consolidation diff than atel becuase no vol loss
Lobar expansion w bulging fissure diagnostic of consol
Bacteriologic classification better than lobar vs bronch

Lobar pneumonia - effects alveoli, Segmental rosetts
exudate spreads contiguosly thru Kohn & Lambert
round in children at times, oblit of vasc markings
Air Bronchograms, frequently cause lobar expansion
Strep pneumonia - #1, diplococcus
Kleb pneumonia - expanded lobe w cavitation suggestive
Bronchopneumonia - lobular, multifocal "patchwork" density
effects term & resp bronchiols, poss vol loss
starts as bronchitis, epithilial destruction progresses to ulcers
acini fill to form nodules, enlarge with spreading
often segmental, mult nodules in other segs R/O atel
NO air bronchograms due to exudate in airways
Pseudomonas - can thrombos pulm arteries
Staph auereus - nec and cavitation
Legionella pneumophila
Most others inc strep, kleb and anaerobes

Acute Interstitial Pneumonia - diffuse reticular nodular
mucus plugs cause atel as in bronchopneumonia
Viruses - cause peribronchial thickening
damage type II cells, dec surfactant prod
Mycoplasma - similar

Aspiration pneumonia - can be Rt side only, clinical risks
segmental consol in dependent portion of lung

TB and Atypical Mycobacteria - adenopathy a key Dx feature
upper or Rt middle lobe involvement
initial exudative phase, vol loss instead of exp
hypersensitivity rxn causes chronic inflam phase
caseation necrosis after 6 wks
Serial screening NOT indicated for screening or F/U

PE - consol from edema, hemorrhage and vol loss primarily
can resemble lobar pneumonia, air bronchograms
confluent densities, irreg border, periph acinar shadows

Neoplasm
Obstructive pneumonia
Bronchioloalveolar cell ca
Lymphoma

Mitral Regurg - pulm edema may localize to Rt upper lobe
Enlarged L atrium occurs BEFORE edema seen

Trauma - can present w lobar consol, usually coalescent
Rib fx frequently NOT present

Sequetration - 2/3 in post left lower lobes

DIFFUSE COALESCENT DENSITIES
Ill defined "acinar" borders, air bronchs
diffuse ground glass pattern of air alveolograms
rapidly changing, usually edema or compromised host

CHF - alveolar edema always preceded by interstitial edema
Cuffing, ceph, eff, enlarged PA, enlarged LV
Periph edema, S3 heart sound, rales, JVD
Gravity dependent, often complicated by infection etc
PE may cause hyperlucent region, bloody pleural eff
can occur w norm size heart

Noncardiac Pulmonary Edema - norm heart best indicator
See also Fine Reticular Densities
Chronic Renal Failure - uremic pneumonitis
cardiomeg assoc
Toxic Inhalation - NO2, sulfur dioxide, CO2, beryllium
acute alveolar infil, no interstitial or vasc changes
resolves in days to wks
bronchiolitis obliterans may develop in wks to months
O2 toxicity can produce hyaline exudate into alveoli
ARDS type presentation results
Smoke inhalation - rxn delayed 24-48 hrs, CO poisoning
check carboxy Hgb levels, >2% or 7% in smoker
Near Drowning - 24-48 hr delay, hypoxia and obstruction
fibrin degradation occurs allowing capillary leak
any airway obstruction or reexpansion similar
ARDS - Increased permeability edema, 5 criteria
Event - shock, trauma, sepsis, OD, pancreatitis
White Out - previously N, No failure
Loss of Compliance - difficult to ventilate
Refractory Hypoxia - requiring oxygen
PO2<60mmHg, PCo2>50mmHg
Shunt - precappilary
persists for wks, retic fibrosis, hyaline mem remain
DIC & or platlet aggregation are mechanism of injury
Morphine Reaction - acute edema IV, idiosyncratic
other drugs like methotrexate also, steroids for Tx
Cerebral Contusion - causes venous constriction, inc cap perm
Upper lobe distribution
Fat or Amniotic Fluid Embolus - 24-48 hr delay, not more
Air Embolus - problems caused by frothing which causes blood clots
place pt in Left Lat decubitus position to keep air in R Vent
Inflammation - bronchiol & alveolar exudate
Brochopneumonia - #1, G- esp produce fulminant pneumonia
freq preceded by multifocal ill defined densities
asym or even unilat common, pt is very sick
Viral Pneumonias - fulminant cases have diffuse consol
usually in compromised pt
Aspiration Pneumonia - usually chronic cases
predisposes to G- pneumonia
Opportunistic Pneumonias - PC, alveoli fill w exudates
reticular pattern can preced or follow, Dx w Bx
cryptococcus, phycomycetes, mucormycosis, cand, asper
Sarcoid - may have alveolar phase, Patchy consol in late phase

Hemmorrhage - hemoptysis best indicator
Anticoagulation therapy
Leukemia - bleeding diathesis is one complication
Infection, drug rxn, edema, leukemic infiltrate also
DIC
Blunt Trauma - usually irregular & patchy, diffuse consol poss
Vasculitis
Infectious - RM spotted fever, fungus, mononucleosis
Wegener's - renal and nasopharyngeal, nec granulomas
Goodpasture's - hemoptysis, hematuria, Dx w renal Bx
cytotoxic antibody mediated immune rxn
alveolar & glomerular basement mem damage by Ab
bilat coalescent densitys, resolve to retic 2days
complete clearance in 2wks unless recurrent
occurs in young males
SLE - often asym even with severe appearance
hemorrhage is the most serious form of lung Dz w SLE
Pulmonary Hemosiderosis - acute alveolar hemmorrhage, idiopathic
multiple recurances, progresses to nodular app or retic fibrosis
tends to accumulate posterior, consider when consol bilat
Alveolar Proteinosis - idiopathic but assoc w altered immunity, Nocardia etc
3:1 male, Defective Macrophage Fxn & impaired surfactant clearance
CXR - alveolar process w fine diffuse perihilar, acinar rossetes
Rare in children, more nodular
Similar to massive silica exposure - silicoprotienosis
CT - Shows prominent septa of unknown etiology
Dx & Tx w bronchial lavage - presence of alveolar phospholip
variable course, WAXES & WANES over wks & months w/o Tx
DDx - pneumonia, edema & hem

Neoplasm
Bronchioloalveolar cell ca - alveoli and dist bronch
air bronchs common, consol, mucus fills alveoli
Lymphoma - localized or multifocal usually, AIDS
Lymphocytic interstitial pneumonitis
Angioblastic lymphadenopathy
Mycosis fungoides
Waldenstrom's Macroglobulinemia

Chronic Granulomatous Dz - II' to AIDS or hemmorrhage
edema obscureing miliary Dz

Pectus Excavatum - can produce paramediastinal density
2nd & 10th ribs turn downward anteriorly
Metastatic Calcification - Calc deposits in base mem of alveoli
occurs in more basic enviroment of UPPER lobes & kidneys
assoc w distant malig & severe renal Dz etc
dec pulm compliance results, often cause of death
Desquamative Pneumonitis

FINE RETICULAR DENSITIES
determine acute or chronic first
Kerley lines - specific indicator of interstitial Dz
Costophrenic on PA, retrosternal on Lat
Engorged connective tissue of interlobar septa
B perpendicular to pluera, A deep in lung parenchyma

ACUTE
1. Interstitial Edema - #1 cause of fine retic pattern
CHF - Persis failure is a poor prognostic sign post MI
if Lt atrium lg, think mitral stenosis

ARDS - Increased permeability edema, 5 criteria
Event - shock, trauma, sepsis, OD, pancreatitis
White Out - previously N, No failure
Loss of Compliance - difficult to ventilate
Refractory Hypoxia - requiring oxygen
Shunt - precappilary

Neurogenic - follows head trauma, seizure or Inc ICP
sympathetic discharge causes inc venous return, UPPER

High Altitude - 48-72hrs P ascent, response to hypoxia
Overflow to unused portions of lung result

Reexpansion - ischemia produced surfactant def
also assoc w free radical prod & endothelial damage

Uremia - due to fluid overload, watch for pnuemonia
Hypoproteinemia - follows cirrhosis, nephrosis etc

Amniotic Fluid Embolism - Mucin & squam cells obs caps
Pulm Htn & Cor Pulmonale result, severe edema, fatal

Fat Embolism - occurs 24-48hrs P Fx, usually mild
fat hydrolyzed to fatty acid, inc cap permiability

Drug Toxicity - Methtrexate & busulfan primarily
Edema follows vascular injury, progresses to hyaline & fibrosis

2. Infection - retic pattern from inflam cells in interstitium
Viral pneumonia, Mycoplasma and PC pneumonia - #2
Mononucleosis & Malaria - plasmodium falciparum


CHRONIC CAUSES OF FINE RETICULAR DENSITIES
serial films document "fibrosing alveolitis"
Unilat = lymphangetic spread of I' lung adenoca til proven otherwise
Pneumothorax can be assoc w any, think LAM or PCP

1. Chronic edema
Mitral Stenosis - #1, look for Lt atrial enlargment
Left Atrial Myxoma - #1 primary tumor of the heart
originates from septa near fossa ovalis, 10% calc
also includes L atrial enlargement as w stenosis
Echo is modality of choice for Dx
DDx - atrial thrombus, both may calc
usually not near septum & more likely in the atrial appendage
Pulm Veno-occulusive Dz - small scattered pulm veins occluded
Aquired but etiology unknown , children <20yrs, rapid death
Dx often made only at autopsy
effects the pulm veins which lie in intralobular septa
Normal Wedge Pressure due to blood draining thru N channles
Sclerosing Mediastinitis

2. Granulomatous Dz
Sarcoidosis - evolution from nodules to lines
steroids make them susceptable to infection
Eosiophilic Granuloma - histiocytes & eosinofils fibrose
Apical Dist, Photographic neg of edema

3. Collagen Vascular Dz - pulm changes in late stage usually
Rheumatoid - assoc w plueral thick & eff, steroid Tx
look at shoulder joint for Dx
interstitial pneumonitis or fibrosis w discrete nodules #1
Scleroderma - lower lobe dist, consol also seen
assoc w aspiration due to severe esoph Dz

4. Neoplasm - lung Bx to exclude opportunistic infection
Bronchoalveolar Ca
Lymphangitic Tumor Spread - usually bilat and basilar
CT very sensitive to brochovasc & interstitial spread
I' lung adeno #1, but breast, GI, pancreas met also
progresses to reticulonodular pattern
Lymph obst by mass - esp sm cell, mets, & lymphoma
Lymphoma & Leukemia - adenopathy suggests this Dx
infection and drug rxn must also be considered
Waldenstrom's Macroglobulinemia
Lymphocitic Interstitial Pneumonitis - rare, more w AIDS
mature lymphocytes in intersitium, NO ADENOPATHY
5. Inhalation Dz - due to intersitial fibrosis
Asbestosis - fibrotic retic pattern in bases, assoc w calc
Mg+ silicate forms silic acid w lung moisture
extensive alveolar wall rxn, FB giant cells seen
talc also contains Mg+ silicate
Silicosis - extensive and progresive Dz, more coarse
Apical retic nodular more common, eggshell calc
Hard metals

6. Idiopathic
Pulmonary Hemosiderosis - follows mult consol
iron laden macrophage fill interstitium of bases
Amyloidosis - rare, but consider in mult myeloma
can be any pattern of infil or nodules, adenopathy & cardiomeg
Drug rxn - bleomycin, busulfan & other cytotoxic agents
Bleomycin causes a dose related pulmonary fibrosis

7. With Pleural Effusion
Acute edema, infection, malaria
Chronic edema, Rheumatiod, ca, Lymphangectasia
Lympangiomyomatosis - women 15-50 only
sm muscle prolif in bronch, venuoles & lymphs
severe obst Dz despite near N' CXR
reccurent chylothorax & pneumothorax common

8. With Hilar Lymphadenopathy
Sarcoidosis, Lymphoma, ca
Silicosis
Viral pneumonia - rare

9. Neurofibromatosis - assoc w fibrosing alveolits
Occurs P 30yrs in 20%, consider only w other Sx of Dz
chest wall fibromas may project also

Upper Lobe Distribution - "CASSET"
Cystic fibrosis, Ank spondylitis, Silicosis, Sarcoid, EG, TB

Lower Lobe Distribution - "BADD LASS RF"
Bronchiectasis, Aspiration, Desquam interstitial pneumonitis, Dermatomyositis
LAM, Asbestosis, Sarcoid, Scleroderma, RA, furantin

Assoc w large lung vol - Cystic Fibrosis, EG, LAM & underlying COPD

COARSE RETICULAR DENSITIES
Honeycomb lung, irreversable
cystic spaces result from retracting fibrosis, periphral
cystic bronchiectasis of cystic fibrosis can mimic, cent
ID of the pattern R/O edema, mets, and viral pneumonia

1. Collagen Vascular Dz - need clinical correlation
Rheumatoid Lung - restrictive, diaph elev bilat
patchy alveolar infil - early fibrinous exudate
fine retic nodular - lymphocytic infil
cellular infil gradually replaced by fibrosis
Scleroderma - similar radiologic progression
thickened alveolar walls replaced by fibrosis
effects LOWER lobes, assoc w cor pulmonale
Pseudosacculations on antimesenteric side of sm bowel
Drug sensitivity and other causes of recur interstitial
infil can progress to this
Ankylosing Spondylitis - upper lobes, look for bamboo spine
retraction, hilar elevation & bullous changes
Mycetomas are freq assoc, cause adj plueral thickening

2. Inhalational
Pneumoconiosis
silicosis - upper lobes, lymphadenopathy, no calc
asbestosis - basilar, assoc w plueral thick, calc Dx
Chemical Inhalation - direct injury causes scarring
NO2 - silo fillers Dz, only w recurrent exposure
sulfur dioxide, Cl, phosgene, cadmium etc
Allergic Alveolitis - fungus allergy like farmer's lung
injury 1st occurs at cap level, edema, cellular infil
Oxygen Toxicity - may improve over months, usually peds
often the cause of fibrosis following ARDS
Chronic Aspiration - ususally localized, assoc w Hx
Mineral oil freq in elderly

3. Inflammation (TB causes bronchiectasis not honeycombing)
Sarcoid - granulomas replaced by fibrosis not necrosis
interstitial nodular initially, adenopathy
Eosinophilic Granuloma - cellular infil prog to fibrosis, 90% smokers
no adenopathy, upper lobe dist, 25% get pneumothorax
one of 3 histiocytosis X processes
Hand-Schuller-Christensen & Letterer-Siwe, peds Dz
EG occurs in 14-40 y/o, more mild
4. Interstitial Pneumonitis - Hamman-Rich Syndrome
Usual Interstitial Pneumonitits - mural type fibrosing alveolitis
injury to alveolar wall, edema, hyaline mem, infil
regenerating epi incorporates the mess into wall
basilar consol, ill defined, 50% honeycomb, 70% die
Desquamative Interstitial Pneumonitis
Desaquamative type of fibrosing alveolitis, 12% honeycomb
more responsive to steroid Tx than UIP, 30% die

5. Lymphangiomyomatosis - young fem, gradually prog dysp
more complete on pg.49 under Reticulonodular Dz

6. Neurofibromatosis & TS - consider only w other signs

Basilar dist - asbestosis, scleroderma, rheumatoid, UIP, DIP
Upper lobe dist - silicosis, EG, tuberculous bronchiectasis
ankylosing spondylitis

MILIARY NODULAR & RETICULONODULAR DZ
1-2mm, best seen in angles on PA, retrosternal on lat
sharp margins exclude edema, hem, or exudate (airspace)
indicates an interstitial process

Don't Eat Spoiled Tuna Fish Sandwiches Very Much
Dust, EG, Sarcoid, TB, Fungus, Schisto, Virus, Mets
first 4 upper & mid, fungus diffuse, last 3 lower

1. Inhalational Diseases - more on pg77
Inorganic Dusts
Fibrotic - Silica, Asbestos
Inert - Iron, Tin, Barium, Antimony
Granulomatous - Berylium
Organic Dusts
Tracheobronchial Hypersensitivity
Alveolar Hypersensitivity
Toxic Chemicals

2. Inflammatory - mild clinically despite severe appearance
Sarcoidosis - bilat hilar adenopath will dec as nod inc
Eosinophilic Granuloma - Langerhan cell infil of lung parench
Strong assoc w smoking in mid age pt's, Adenopathy in kids

3. Infectious
Endemic Mycosis - infect healthy host, equal upper & lower Dist
Histoplasmosis - #1, Minimal initial response, No pneumonia, asym
allows for freq dissem to lymphnodes & spleen
Blastomycosis - 15um yeast, endemic more NE than histo
Early pyogenic response w pneumonia prevents spread
Coccidiomycosis - 60um yeast, by far the most virulent
Early pyogenic response w pneumonia prevents spread
Chronic - mult cavities w thick or thin walls, sim Sarcoma
Opportunistic Mycoses - weak pathogens, compromised pt's
Aspergilla - second most common fungus, colonize 16% of N pts
Cystic Fibrosis & Asthma pt's susceptable
Allergic Bronchopulmonary Aspergillosis - bronchi colonize
Mycetoma - Arise in Pre-existing cavities or TB, sarcoid
hemoptysis is a common complication
Invasive Aspergillosis - assoc w neutropenia, fatal in 70%
Chronic Necrotizing Aspergillosis - semi-invasive in tiss
NO vasc invasion, can still have hemoptysis
Cryptococcus & Candida - rare pulm involvement

TB - miliary, severe febrile, sputum may be neg, need Bx

Bacteria
Nocardia - G+ seen in immune comp
May induce Alveolar Proteinosis - see #7 below
Salmonella - unusual

Varicella Pneumonia - rapid prog to coalescent densites
occurs in 10% of adults, 2-5 days p onset of rash can
heal as mult sm calc

4. Metastasis - severe illness, R/O opportunistic infec w Bx
Any ca which undergoes lymphangitic spread
Thyroid ca, Melanoma, Adenoca of GI, Breast, Renal Cell, etc

5. Lymphangiomyomatosis - hamartomatous smooth musc proliferation
surrounds & obstructs lymphatics, venules & bronchioles
Presentation - hypoxia, INCREASED total lung capacity & poor diffusion
aggrevated by birth control, dead within 10yrs
CXR - Bilat symetric diffuse Retic-nod pattern top to bottom
Pneumothroax & Chylous eff are typical presentation
can progress to "Honeycomb" pattern, 10yr survival
HRCT - Mult sm cysts form w intervening septa of N tissue
Lymphadenopathy due to lymphatic infil w sm musc
Renal Angiomyolipoma seen in 15%
DDx - EG, but cysts are thicker, no chylous eff & it spares lung bases
both EG & LAM present w pneumothorax
Tuberous Sclerosis - rare presentation, does not have eff & involves CNS
Benign Metastasizing Leiomyoma - see mult nodules

6. Tuberous Sclerosis - Perivascular Sm musc prolif, Auto Dom
Pulm involvement in 1% - identical to Lymphangiomyomatos
50% have CNS involvement not seen in LAM
7. Alveolar Proteinosis - usually only reticulonodular in children
"Edema" type pattern in adults

8. Also
Bronchiolitis obliterans - Sweyr-James, unilat hyperlucent lung #1
Alveolar microlithiasis - rare, idopathic, spares the interstitium
diffuse involvement of both lungs
50% familial, usually asym
Gaucher's Dz
Wegener's granulomatosis - usually seen w coalescent den
Hemosiderosis - fibrosis allows mult hem

Afebrile pt - Inhalation Dz, EG, sarcoid, mets, miliary TB
late fungal infection

Febrile pt - TB, nocardiosis, viral pneumonia, early fungal
allergic alveolitis may cause mild febrile resp
steroids inc chance of infec, suppres response

MULTIFOCAL ILL DEFINED DENSITIES
mixed interstitial & alveolar proc, signs of both
air bronchs, alveolagrams, coalescents, & retics
1-3cm areas, often II' to obs from I' process

1. Inhalational
Allergic Alveolitis - inflam infil, prog to gran rxn
Silicosis - irreg rather than ill defined, no air bronch
II' to fibrotic rxn around conglomerate masses

2. Inflammatory - asym or mild dysp, afebrile
Sarcoidosis -adenopathy, noncas gran
this pattern more likely than bilat confluence
peribronch obst by gran may account for this
EG - See seg on Fine Nodular pattern, upper lobe dist
CT shows mult subplueral nodules
Rheumatoid Arthritis - causes Caplan Syndrome
multifocal densities, freq calc & cavitation
3. Infectious casuses of Multifocal Ill Defined Density
Bronchopneumonia - most common presentation
term & resp bronchial ulcerations
staph & pseudomonas nec atrerioles, acini fill
prog to multi lobar, cavitate, diffuse if comp pt

Viral & Mycoplasma pneumonias - retic pattern #1
cellular septal infil, can prog esp in comp pt
acini fill, hyaline mem form, nec and hem
Rubeola - appears w rash, II' bac infec 1-7d p
CMV - look for cytoplasmic inclusion bodies

Fungal pneumonia - histo #1. coccidio & blasto also
Bx comp pt to R/O crypto, aspergil, & mucormycosis
TB - rare presentation unless preceded by an apical cav

Bronchiolitis obliterans - follows toxin or infec expos
gran tissue plugs sm airways, II' pneumonia seen freq
similar but less severe than Swyer-james syn, UIP sim

Eosinophilic Pneumonia - peripheral, coales, air bronch
Recurrent and migrating desities in periph diagnostic
Eosinophils in airspaces & interstitium
Upper lobe involvement ONLY, Photographic Neg of Edema
Loeffler's Syn - transient, pulm phase of parasites
Assoc w chem inhalation, asthma & hypersensitivity
Transient parench consol assoc w blood eosinophilia
Sulfonamides - pulmonary toxic
Tropical Pulmonary Eosinophilia - filariasis, a threadlike nematode
infected by mosquito bite, peripheral eosinophilia assoc
Chronic Eosinophilic Pneumonia - Idiopathic
80% elderly female, 30% atopic asthmatic
Migratory peripheral pattern lasting >3mo
ASK - does pt have peripheral Eosinophilia
yes for pneumonia type, no for EG type
Dx - resolves rapidly w steroid Tx, may recur

Rocky Moutain Spotted Fever - art vasculitis
Nocardia - Alveolar Proteinosis may have this pattern
PCP
4. Hemorrhage
Wegener's Gran - vasculitis, necrotizing granulomas & hem due to ischemia
diffuse dist, cavitates, nasal and tracheal involvement also
lymphoid granulomatosis - variant c hilar nodes, poss lymphoma
Goodpastures Syndrome - Diffuse patchy & acinar consolidation Bilat w hilar & lower distribution, onset approx 25yrs, 7:1 male
Can resolve rapidly, later progessive fibrosis poss Idiopathic Pulmonary Hemorrhage - present same as Goodpasture
Dx by exclusion, 2-5yr surv in kids, longer in adult
Tx supportive only, can lead to MILD fibrosis if recurrent
Immune Complex Dz - Trapped in renal & vasc but not BM
present same as Goodpasture's, Ab complex in circulation
SLE - most serious lung manifestation, usually late phase
Thromboemboli - basilar, seg dist, edema not infarct
area dec in size over time to linear scar
Septic Emboli - inc incidence of cavitation
Infectious vasculitis - mucormycosis invades arteries
rickettsia and aspergilla also

5. Neoplastic
Brochioloalveolar Cell ca - the only I' w this pattern
spreads along alveolar wall and leaves them intact
copius mucus prod, air bronchs seen, bronch spread
Lymphoma - spreads thru con tis, obs causes infil
angioblastic lymphadenopathy, waldenstom's macro also
Kaposi's Sarc - usually more diffuse retic, follows skin
Choriocarcinoma met - rarely

6. Idiopathic - require Bx for Dx
Lymphocytic Interstitial Pneumonitis - dump cells in alv
Desquamative Interstitial Pneumonitis or UIP
Drug rxn - more often coalescent peri hilar like edema
respond rapidly to steroids though, so alveolar also
Radiation rxn

NEOPLASTIC PULMONARY MASSES
Sharply defined, homogeneous, no infiltrative signs
CXR detects nodules 4-40mm, CT detects .5-17mm

MALIGNANT NEOPLASM
1. Metastases - #1cause of mult nodules, all but CNS tumors met to lung
unusual presenting c/o except w testicular ca
sharply defined unless hem present, then fuzzy border
Calc - rare, chondrosarc, mucious adenoca & cystadeno
Osteosarcoma - Cloudlike osteoid w peumothroax
Dystrophic calc seen post therapy
Cavitation - assoc w squa cell, any can cavitate
Spindle cells actually cav more often, but rare
can have very thin "coccidiomycosis" type app
Double Time = time to inc dia by 25%
Thyroid Ca & Adenoid Cystic Ca very slow, years
Melanoma can double in <2wks
Lymphangetic Carcinomatosis - spread in from lung
only I' lung ca spreads out from nodes
Desmoplasia elicited by adenoca actualy visualized
nodular thickening along septa, Eff often assoc
Endobronchial mets - freq but rarely seen grossly
Met can be removed if under 2cm each

2. Lymphoma - usually infiltrative

3. Krukenberg Tumor - simultaneous GI & ovarian adenoca
may present as met to lung


BENIGN NEOPLASM
All are rare
1. Hamartoma - #1 benign tumor, 5% of SPN's, 3:1 older females
Cartilage & fat w surrounding fibrosis, 90% asym & solitary
CXR - well marginated spherical w poss lobulations, <4cm
"Popcorn" calc in 10%, slow growth
CT - Fat w HU -80 to -120 pathog, often assoc w calc

2. Carney's Triad - Pulmonnary Chondromas, 2:3 female <20yrs
Gastric leiyommas & Extra Adrenal Paraganglioma complete triad
3. Laryngeal Papillomatosis - aspirated by infant from mothers inf
Children 18mo-3yrs, lung lesions seen 10yrs later
most common laryngeal tumor in children, present w stridor
CXR - diffusely infiltrates into lungs w freq cavitation
Always assoc w endobronchial lesions

4. Leiomyoma - solitary smooth musc neoplasm, I' or metastatic
90% asym, middle age pts, slight predilection to females
CXR - smooth well circ solitary nodule, usually peripheral
Calc & cavitation poss but rare

INFLAMMATORY CAUSES OF PULM NODULES

1. Fungal
Histo - confirm c skin test
Coccidio - flu like Sx, nodules cav, serologic Dx
Crypto - Bx for Dx, may assoc c crypto meningitis

2. Nocardiosis - comp pt, has many manifestations

3. TB - central calc means TB or histo, watch for assoc ca
eccentric calc may be adj to ca

4. Parasites
Hydatid cyst - echinococcus granulosus, dog tape worm
air meniscus & floating parasite may be seen
Paragonimiasis - snail fluke, infects crabs then eaten
thru diaph to lungs where eggs shed, hemoptysis

5. Septic emboli - become circumscribed as lesion heals

6. Sarcoid - usually more ill defined nodules, asym key
resolve spontaneously

7. Inflammatory Pseudotumors
Fibrous Histiocytoma
Plasma cell granuloma
Hyalinizing pulm nodules

VASCULAR CAUSES OF PULM NODULES
1. Atriovenous Malformation - Comm from pulm art to pulm vein
Young female, LOWER lobe, most asym, 50% not assoc w syndrome
Shunt can allow systemic emboli, inc CO w N Pulm art P
Angio - lolypop appearance dangling from art, early drain V
CXR - thin vasc walls can result in focal paranchymal hem
Usually well circ, draining vien often visible, 60% solitary
if multiple think of hereditary telangiectasia
CT - intense contrast enhancement unless thrombosed
Shunting - assoc w Hypertrophic Osteoarthropathy
also inc risk of sytemic emboli, CVA, brain abcess & hemoptysis
Tx - embolization, if pulm HTN assoc cor pulmonale may result

Osler-Weber-Rendu - hereditary hemorrhagic telangiectasia, auto dom
Skin & mucosa are I' sites, lung involved in 20%

2. Pulmonary Varix - nonobstructive dil of pulm vein, no desaturation
dilation seen near L atrium, histologically Normal
Assoc w Pulm venous HTN & aquired heart Dz w lg L atrium

3. Pulmonary Art Aneurysm - Congen or aquired
Swan-Ganz #1 - Hemoptysis assoc fatal in 50%
TB & mycotic aneurysms also

4. Organizing infarcts - become more circumscribed
Wegener's Granulomatosis - extensive Dz causes infarcts
wegener's triad - lung, kidney, sinus Dz
Rheumatoid lung - type III hypersensitivity, IgM pos
interstitial pneumonitis or fibrosis w discrete pulm nodules
Necrobiotic nodules - periph or pluer, thick walled
Caplan syn - coal pneumoconiosis + rheumatoid

5. Amyloid - deposits of short chain Ig, 90% Primary type in lung
Nodules - firm w sharp borders, even mult often asym
NO assoc fibrosis, usually elderly pt
Interstitial - Reticulonodular w severe restp distress
Diffuse & bilat, Dead in 6mo
DDx - miliary TB, silicosis, sarcoid
Secondary Amyloidosis - RA, Malig neoplasm, Mult Myeloma, inf

6. Post Traumatic

DIFFERENTIAL FOR A SOLITARY PULMONARY NODULE
Do CXR w 120-150Kvp for mediast visualization
Calc best detected at 68 Kvp, or w CT densitomitry
Always obtain old films to asses a nodule
flouroscopy most expeditious way to R/O rib, plueral etc
Bx most often needed for Dx

1. Fake Outs
Artifacts - buttons, snaps
Nipple shadow
Skin lesions - mole, lipoma, neurofibroma
pleural lesions - loc eff, mass
fluid in interlobar fissure

2. Malignant Neoplasm
Bronchogenic Carcinoma
Bronchial adenoma - can be well circumscribed, may calc
Carcinoid - arises in prox bronch, may seed to periph
Mucoepidermoid
Adenoid cystic
Lymphoma - interstital spread
can imitate organizing pneumonia etc
Mets
Primary sarcoma of lung
Plasmacytoma

4. Benign Neoplasm - slow growth, 18mo doubling time
Hamartoma - often lobulated, 20% calc "popcorn", fat
Chondroma
Lipoma or fibroma
Lymph node
Neural tumor
Inflammatory pseudotumor

5. Inflammatory
Granuloma - calc should be >10% of nodule, sym & smooth
<3cm and stable over 24 mo
Plasma cell granuloma - idiopathic colletion of inflam cells
only 20% follow pneumonia
rarelly calc or cavitate, Dx made w resection
Abscess
parasite
Organizing pneumonia
6. Vascular
AVM - look for lg vessels assoc, draining vein esp on CT
hemoptysis #1, shunting, dyspnea, polycytemia, CHF
60% assoc w Osler-weber-rendu - GI bleeding, or CVA assoc
CXR - well defined & lobulated, medial 1/3 of lung
change in size w valsalva
Organizing infarct - can have ill defined margin like ca
will reduce in size over time
Pulm vein varix - occurs near entrance to lt atrium
valsalva will dec the size, angio to DDx from AVM
Hem due to Rheumatoid nodule or Wegener's
Hemangioma - phleboliths
Extramedullary hematopoiesis

7. Developmental
Bronchogenic cyst - fluid filled
Sequestration - most often seg consol in L lower lobe

8. Inhalational
Silicosis - conglomerate mass
Mucoid impaction - follows aspergilla allergy
Paraffinoma - lipid granuloma
FB aspiration

9. Children
Mets - #1 site for Wilms, Osteosarc assoc w pneumo
neuroblastoma, ewing's
Blastoma
AVM, hemangioma, Hamartoma
Granuloma - can be residual of atypical measles
Organizing pneumonia
Bronchopulmonary sequestration, Bronchogenic cyst

HYPERLUCENT THORAX
pathologic lucency due to air or lack of vasc

1. Technique - always the FIRST consideration
Overpenetrated film - low Kvp can cause high contrast
Assoc w bilat mastectomy or thin pt
Faulty technique - ie rotation
Check for Mastectomy or absent pectoralis muscles

2. Bilateral
Cardiac Dz - Rt to Lt shunt obs pulm flow
TOF #1, infundibular pulm sten & VSD bypass pulm flow
pulm vasc sm prox and distally
Truncus arteriosus type IV
Pseudotruncus arteriosus
Tricuspid atresia
Eisenmenger's complex - due to long standing Lt to Rt
endarteritis obliterans that dec periph vasc
massive prox dilation develops due to inc resis
serial CXR will show prog from dil pulm to above
in late stage shunt may reverse causing cyanosis
Asthma - acute air trapping
attenuation of vasc markings, deppresed diaph
acute bronchiolitis - Pediatric, both transient
confirm w expiratory films
Emphysema - dec vasc markings most reliable sign for Dx
CT sensitive for early detection of dec art & bullae
Panlobar - destruction dist to term bronch, basilar
Centrilobar - #1, dest to center of lobe, upper dist
PE - bilat lucency follows complete pulm outflow obs
Pulmonary Sling - Aberrant L pulm art arises from R side
presents in infancy, compresses post trachea as it crosses
passes between trachea & esophagus
Polychondritis - collapses cartilage rings cauesing air trapping
also note collapsed vert disks

3. Unilateral Lucent Thorax
Pneumothorax - Trauma #1 etiology, Osteosarc mets
assoc w Sarcoid, Histiocytosis, Lymphangiomyomatosis, TB
Spontaneous Pneumothroax more common in men, 20-30yrs
Catamenial Pneumothorax - occurs w endometriosis
implansts cause monthly cycle of pneumothroax
Mediastinal emphysema
Sub Q emphysema
PE - Westmark's Sign, localized lucencies from sm PE
Plueritic CP, dyspnea, apprehension, +VQ, +angio
also assoc w adhesive atelectasis due to loss of surfactant
Emphysema - esp bullous
Swyer-James or Macleod's Syn - Bronchiolitis obliterans
follows viral pneumonia, esp adenoviral bronchiolitis as infant
diffuse fibrosis of bronchiols causes air trapping
tends to hyperinflate alveoli & compress, NO wall destruction
severe unilat & patchy hyperinflation, "Pruned Tree"
effected lung N w inspiration, traps air w expiration
Compensatory Overaeration - post surgical
Congenital lobar Emphysema - see neonatal chest section
Cardiomegaly - Lt lower lobe

4. Bronchial Obstruction - causes dec perf of vasc bed,
inc flow to N lung, mediast shifts to N side, dep diaph
confirm w exp film, flouro, lat decub
colateral air drift I' means of hyperinf beyond obs
Bronchogenic ca
Mets
Granulomatous masses - broncholith
Bronchial mucocele
FB

SOLITARY LOCALIZED LUCENT DEFECT
DDx is a cavity, cyst or pneumatocele
cavity - II' to necrosis, fluid out & air in thru bronch
wall created by cell infil, hem, edema & comp N lung
surrounding retic indicates old, edema is newer
CT can detect before drainage of liquid
Cyst - may displace healthy tissue around it

1. Inflammation
Abscess - acute or chronic pyogenic infec, staph & G-
vasculitis & thrombosis usual mech
staph, Kleb, Pseudo, G-, B hemolitic strep, anaerobes
never viral or mycoplasm, rarely strep pnuemo
toxic febrile course, copious sputum
Pulmonary Gangrene - acute nec of lung tis
detaches viable lung, mass left lying in cavity
Fungal Infection
Histo - can mimic TB, check PPD & histo skin tests
Coccidio - granulomatous and can mimic TB
Cavitate w variable wall thickness, location can vary
Blasto & Crypto
Mucormycosis - can cause pulm gangrene
Mycobacterial infection - granulomatous cav, pt less sick
TB - cavitation II' to hyperimmune Rxn, bugs released
inc risk for bronchial or hematogenous spread
retic scars, vol loss, plueral thickening & calc
Atypical mycobacterium - mult thin walled cav, -PPD
Nocardiosis - G+ seen esp in renal transplant pt
Sarcoidosis - expanding fibrosis NOT cavity

2. Neoplasms - 16% cavitate, fluid levels can occur, Bx to Dx
nodular wall does not reliably DDx from abcess
Epidermoid ca - #1 w 30% cavitation
Bronchioloalveolar cell ca - #2, very well diff adenoca
Mets - usually multiple
Squamous cell - #1, nasopharynx, esophagus, cervix
Adenoca - lung, breast, GI
Osteosarc - rare
Melanoma

3. Vascular - usually multiple lesions
Rheumatoid & Wegener's - likely to cause vasc inflam
Infarct - thrombo or septic

4. Congenital
Bronchogenic Cyst - always has smooth thin wall, congen
simple cyst usually present as mediast mass
14% present in lung, 36% w air space
Dx by exclusion, can mimic coccidio
Sequestration - most often segmental consolidation in L lower lobe
Bronchiectatic Cyst - usually multiple, basilar
aortagram will differentiate from sequestration

5. Trauma or Insult to Parenchyma
Brochopleural Fistula - rupture II' to infec etc
hydropneumothorax common
Pneumatocele - infectious or traumatic cysts, air traped
occur in healing phase & multiply, often transient
staph & hydrocarbon pneumonia common etiologies
Bullous emphysema - multiple thin walled periph & apical
attenuation of vasc, assoc w pneumothorax

MULTIPLE LUCENT LESIONS
1. Infection - #1, assoc w extensive airspace consol
Pyogenic Infection - three sources of lucency
intervening N lung
pneumatoceles - discreet smooth walls
nec of tissue - sick, AF levels, thick wall
Granulomatous - TB, histo, coccidio, blasto: INDOLENT
apical cavities w assoc retic lung diagnostic
occurs during II' hyperimmune phase
Primary progressive TB - cav without dormant phase
Blasto and coccidio may also cav primarily
Coccidio - thin walled cav, min local rxn

2. Neoplasm
Mets - #1, freq have thick nod walls, sm outer shell
60% epidermoid - head & neck, esoph, cervix
Primary ca - rarely multiple
Lymphoma - rarlely cavitates, may consider if w nodes
opportun inf II' to Tx more likely cause mult cav
may cavitate after radiation

3. Vascular Causes of Mult Lucencies
Thromboembolism - usually N CXR, eff, atel, consol
westmark's sign - hyperslucent patches
cavitation is the only sure sign of true infarct
Septic Emboli - more likely to cav, assoc w Hx of inf
Wegener's - multifoc ill def densities form mult cav
due to diffuse vasculitis, assoc w kidney Dz
Rheumatoid - mult cav, but less common

4. Cystic Bronchiectasis - due to recurrent or chronic inf
Inflam of bronch walls cause them to dilate
Inflam also causes inc bronchial art supply, source of hemoptysis
basilar, first cylindrical then saccular, AF levels
can mimic cavitation, often assoc w cystic fibrosis
Ring shadows - abn dilated bronchi near hila & apex
signs of air trapping w dec vasc & flat diaph
Agammaglobulinemia - can cause recur bac infection
TB & histo - can be a cause and combine cysts w cav
look for assoc loss of vol and apical plueral rxn
Allergic bronchopulmonary aspergillosis - can cause
assoc w asthmatic pts, spares dist bronchi
elev preciptin levels confirm aspergilla
5. Pneumatoceles - usually mult thin walled cysts, AF levels
often found at site of previous pneumonia, pos transient
seen paramediastinally assoc w vent trauma
follow pulm lac which initially fills w blood
PC - common cause in AIDS pts

6. Congenital Lesions - bronchogenic cyst & seq rarely mult, lower lobes
Cystic Adenomatoid Malformtion - rare, hamartoma
Large & noncompressible, can shift mediast & compress IVC
Polyhydramnios, Fetal Hydrops & Pulmonary Hypoplasia assoc
Microcystic - Hyperechoic & solid appearing on US, less common
poorer prognosis, generally do well if survive delivery
Macrocystic - percutaneous aspiration poss, usually reaccum
Have been succesfully resected in utero
occasionally regress in utero w/o intervention

Congenital Lobar Emphysema - unilat hyperlucent lobe w no septa
50% in L upper lobe, 35% in R middle lobe
80% present w Sx within 6mo, 30% have a VSD or PDA

7. Bullous Emphysema - obstructive Dz
often seen early in AIDS pts
freq recurrent pneumothoraces

1-2mm collimation done at a bone algorythm (high spatial freq)
small FOV and narrow window - W2000, L-600
Bronchiectasis & Hemoptysis - do at 10mm intervals thru chest
Diffuse infiltrative Dz - do 4 represenitive slices prone & supine
Suspected small airway Dz do inspiratory & expiratory
defined by 6 primary patterns

1. Septal Lines - extend from outer margin, if seen they are thick
Edema - smooth w assoc ground glass opacities
clinical Dx, give lasix and they clear, assoc cardio
Lyphangitic Carcinomatosis - nodular septal thickening
assoc discrete nodules, no fibrosis

2. Reticular Lines - irregular with diffuse distribution
Usual Interstitial Pneumonia (UIP) - grab bag of "unkown etiology"
Subplueral, peripheral & basilar usually, Honey Comb pattern
ground glass opacity assoc w "active alveolitis"
Sarcoid - more central dist, thick bronchovasc bundle assoc
Asbestosis - sim UIP but look for assoc plueral plaques

3. Air Cysts - Round & Displace normal lung
UIP - honeycomb pattern in periphery has thick round cysts
Lymphangioleiomyomatosis - scattered thin walled cysts
look for assoc chylous effusion, pneumothroax & adenopathy
Eosinophilic Granuloma - scattered thick walled cysts
mid to upper lung, spares costophrenic angles, pneumo, bone lesions
PCP - upper lobe dist & ground glass opacities
Bronchiectasis - tend to be more tubular, "signet rings" seen on end
DDx - Emphysema, tends to be more polygonal
bronchovascular bundle spared & seen w emphysema, not cysts
paraseptal type often one layer, UIP cysts form mult layers

4. Nodules
Sarcoid - more central, become confluent along bronchovasc bundle
can form conglomerate mass like pneumoconiosis
Pneumoconiosis - post upper lobe, focal emphysema assoc
EG - mid to upper lung, may cavitate
Hypersensitivity Pneumonitis - tend to be more ill-defined "alveolar"
5. Ground Glass Opacities - narrow window can help
Alveolar Proteinosis - "crazy paving" pattern of distribution, peripheral
PCP - "patchwork" pattern, thin walled cysts & cavities, central
Desquamative Interstitial Pneumonitis (DIP) - diffuse or lower lobe
less fibrosis than UIP, possibly a spectrum
Hypersensitivity Pneumonitis - diffuse w superimposed nodules
"Mosaic Perfusion" - look at assoc vessels & bronchi
Dilated vessels in dense region indicate vascular congestion
Obstructed bronchi cause regions of low density that are abnormal

6. Consolidation
BOOP - bronchiolitis obliterans organizing pneumonia
subplueral, lower lobe consolidation w assoc bronchial thickening
peribronchial nodules & thickening are key to Dx
Chronic Eosinophilic Pneumonia - peripheral upper lobe, minimal fibrosis
Bronchoalveolar Carcinoma & pulmonary Lymphoma also