Pulmonary pathology II

Question 1

Diffuse alveolar hemorrhage histology

Answer 1

Blood and iron-containing macrophages within airspaces, Alveolar septa may be mildly thickened by inflammation and fibroblastic tissue. May be associated with capillaritis (neutrophils attacking the capillaries of the alveolar septa

Question 2

Pulmonary Alveolar Proteinosis histology

Answer 2

Airspaces filled with pink fluid and macrophages

Question 3

Usual Interstitial Pneumonia (UIP) histology

Answer 3

Patchy heterogeneous fibrosis of the septa by mature collagen. Fibroblastic foci (compact collections of fibroblasts and myxoid stroma buldging into the airspaces). Honeycomb cystic change (end-stage lung remodeling with mucus filled cysts lined by airway-type epithelium and surrounded by fibrosis)
Patchy heterogeneous fibrosis of the septa by mature collagen. Fibroblastic foci (compact collections of fibroblasts and myxoid stroma buldging into the airspaces). Honeycomb cystic change (end-stage lung remodeling with mucus filled cysts lined by airway-type epithelium and surrounded by fibrosis)

Question 4

Which part of the lung displays worse honeycombing in UIP?

Answer 4

lower lobes

Question 5

NonSpecific Interstitial Pneumonia (NSIP) histology

Answer 5

Uniform homogenous inflammation, fibrosis or a mixture of both. Few if any fibroblastic foci. Little if any honeycombing

Question 6

Hypersensitivity Pneumonia (HP) histology

Answer 6

Airway-centered chronic inflammation (lymphocytes and histiocytes). Nonnecrotizing granulomas. Focal organizing pneumonia. Variable fibrosis by mature collagen

Question 7

What causes hypersensitivity pneumonia?

Answer 7

A response to foreign antigens (birds, mold, hot-tub mycobacterial antigens, etc.)

Question 8

Thromboembolic disease histology

Answer 8

Organizing fibrin clots within pulmonary arteries. May form in situ (thrombus) or move to the lung from elsewhere (embolism)

Question 9

Talc embolisms histology

Answer 9

Polarizable crystals around vessels. May include foreign-body giant cells. Usually from intravenous drug use

Question 10

Pulmonary hypertension histology

Answer 10

Muscular hypertrophy of pulmonary arteries. Muscularization of arterioles (normally should not contain smooth muscle). Some forms have plexiform lesions (the artery lumen replaced by endothelial proliferation with numerous tangled slit-like lumens)

Question 11

Vasculitis histology

Answer 11

Inflammation of the vessel wall, Often results in alveolar hemorrhage, May be autoimmune or infectious
Inflammation of the vessel wall, Often results in alveolar hemorrhage, May be autoimmune or infectious

Question 12

Sarcoid / Chronic beryllium disease nodules

Answer 12

Well-formed coalescing nonnecrotizing granulomas (must exclude infectious etiology). Variable concentric collagen deposition around granulomas. “lymphatic distribution” = found next to blood vessels, airways and in the pleura

Question 13

Pulmonary Langerhans’ Cell Histiocytosis (PLCH) / Eosinophilic Granuloma (EG) histology

Answer 13

Cellular phase: Langhans histiocytes (S100, CD1a positive) and Variable inflammation including eosinophils.
Fibrotic/burnt-out phase: Stellate scar around airway.
Usually smoking-related if limited to lung
Cellular phase: Langhans histiocytes (S100, CD1a positive) and Variable inflammation including eosinophils.
Fibrotic/burnt-out phase: Stellate scar around airway.
Usually smoking-related if limited to lung

Question 14

Carcinoid nodule histology

Answer 14

Nests and ribbons of neuroendocrine cells with powdery salt-and-pepper chromatin. Stain positive for neuroendocrine markers (chromogranin, synaptophysin, CD56). Usually indolent, but may act in a malignant fashion particularly if there is nuclear atypia, high mitotic rate or regions of necrosis

Question 15

Small cell carcinoma histology

Answer 15

Small blue easily-crushed cells with scant cytoplasm. Stain positive for neuroendocrine markers (chromogranin, synaptophysin, CD56). High mitotic rate and abundant necrosis

Question 16

Squamous cell carcinoma histology

Answer 16

Large polygonal cells with hyperchromatic (dark) nuclei and abundant cytoplasm. Rarely have prominent nucleoli. May be keratinizing and form ‘keratin pearls’

Question 17

Adenocarcinoma histology

Answer 17

Cells with large nuclei, large nucleoli and variable amounts of cytoplasm. Form gland-like structures. If cells only line the alveolar septa but do not invade, considered adenocarcinoma in situ (formally known as bronchioloalveolar cell carcinoma)

Question 18

Large cell carcinoma histology

Answer 18

Large, sometimes bizarre-appearing, malignant cells that lack the typical features of either squamous cell carcinoma or adenocarcinoma