Lung Flashcards
Congenital pulmonary-airway malformation: Blood supply.
Derived from the pulmonary circulation.
Congenital pulmonary-airway malformation: Definition.
Malformation of part of the lung parenchyma, with abnormal direct connections to the normal tracheobronchial tree.
Congenital pulmonary-airway malformation, type 0: Gross pathology.
Lung parenchyma appears solid.
Congenital pulmonary-airway malformation, type 0: Histology (2).
Disorganized proximal airways; no distal airways.
Intervening tissue consists of connective tissue, thick-walled arteries, and extramedullary hematopoiesis.
Congenital pulmonary-airway malformation, type 1: Gross pathology.
Medium and large interconnecting cysts, usually limited to one lobe.
Congenital pulmonary-airway malformation, type 1: Histology.
Cysts are lined by bronchial epithelium and often contain bands of smooth muscle.
Congenital pulmonary-airway malformation, type 2: Gross pathology.
Back-to-back cysts, smaller than the cysts of type 1.
Congenital pulmonary-airway malformation, type 2: Histology.
Cysts are separated by alveolar ductlike structures, blood vessels, skeletal muscle.
Congenital pulmonary-airway malformation, type 2: Associations.
Sirenomelia.
Renal malformations.
Diaphragmatic hernia.
Cardiovascular abnormalities.
Congenital pulmonary-airway malformation, type 3: Gross pathology.
Solid mass involving the lobe or the entire lung, with hypoplasia of the other lung.
Congenital pulmonary-airway malformation, type 3: Histology.
Glandlike structures lined by low cuboidal epithelium.
Congenital pulmonary-airway malformation, type 3: Associations.
Male sex.
Polyhydramnios.
Congenital pulmonary-airway malformation, type 4: Gross pathology.
Peripherally located cysts of variable size.
Congenital pulmonary-airway malformation, type 4: Histology.
Cysts can have thick walls and are lined by a single layer of pneumocytes.
Capillary beds beneath the epithelial lining.
Congenital pulmonary-airway malformation, type 4: IHC.
Pneumocytes express TTF-1 and surfactant proteins A and B.
Congenital pulmonary-airway malformation: Limitations on diagnosis.
Diagnosis cannot be made when there is chronic inflammation and fibrosis.
Bronchopulmonary sequestration: Definition (2).
Anomalous segment of lung has no connection with the normal tracheobronchial tree.
Blood supply comes from the systemic circulation.
Bronchopulmonary sequestration: Types (2).
Intralobar.
Extralobar.
Bronchopulmonary sequestration, intralobar type: Typical location.
Lower lobe.
Bronchopulmonary sequestration, intralobar type: Gross pathology (3).
No pleural covering.
Sharply demarcated from the normal lung tissue.
May have vascular pedicle.
Bronchopulmonary sequestration, intralobar type: Histology (3).
Marked chronic inflammation.
Mucus accumulation and microcyst formation.
Dense fibrosis surrounds remnants of bronchioles.
Bronchopulmonary sequestration, extralobar type: Typical location.
Left side.
Bronchopulmonary sequestration, extralobar type: Gross pathology (2).
Covered with visceral pleura.
Separate from normal lung tissue.
Bronchopulmonary sequestration, extralobar type: Histology (3).
Enlarged bronchi, bronchioles, alveoli.
No significant inflammation or fibrosis.
Dilated subpleural lymphatics.
Bronchopulmonary sequestration, extralobar type: Association.
Congenital pulmonary-airway malformation, type 2, is present in up to half of cases.
Bronchogenic cyst: Origin.
Anomalous budding of the tracheobronchial anlage during development.
Bronchogenic cyst: Most common site.
Mediastinum.
No communication with the tracheobronchial tree.
Bronchogenic cyst: Radiography.
May have an air-fluid level.
Bronchogenic cyst: Histology (3).
Epithelial lining and wall (smooth muscle, cartilage) resemble those of a normal bronchus.
Squamous metaplasia or chronic inflammation may occur.
No alveolar tissue.
Congenital lobar emphysema: Definition.
Hyperinflation of one or more lobes of the lung.
Congenital lobar emphysema:
A. Age at presentation.
B. Most common site.
A. Within 6 months after delivery.
B. Left upper lobe.
Congenital lobar emphysema: Radiography.
Compression of contralateral lung and mediastinal shift.
Congenital lobar emphysema: Histology.
Alveolar distention without fibrosis.
Congenital lobar emphysema: Etiologies.
Idiopathic: Most cases.
Intrinsic compression of the bronchus supplying the affected lobe: Structural defect of bronchus.
Extrinsic compression: Mass.
Chronic bronchitis: Histology.
Reid index >0.5 (glands make up more than half the thickness of the bronchial wall).
Mild chronic inflammation.
Asthma: Gross pathology (3).
Hyperinflated lungs.
Mucous plugging of airways.
Saccular bronchiectasis.
Asthma: Histology (3).
Mucous plugs containing eosinophils.
Fibrosis beneath the basement membrane with patchy loss of epithelium.
Thickened walls of airways due to edema, hyperplasia of smooth muscle, increased mucous glands.
Asthma vs. chronic bronchitis.
Chronic bronchitis: Few or no eosinophils.
Bronchiectasis: Definition.
The bronchus is wider than its bronchial artery.
Bronchiectasis: Clinical presentation.
Persistent cough.
Copious, foul-smelling sputum.
Bronchiectasis: Causes (8).
Primary ciliary dyskinesia. Rheumatoid arthritis. Immunodeficiency. Cystic fibrosis. Inflammatory bowel disease. No known cause (30%). Graft-versus-host disease.
Infections.
Bronchiectasis: Histology (2).
Mucosa: Variable inflammation, reactive changes, necrosis.
Wall: Chronic inflammation, fibrosis.
Middle-lobe syndrome:
A. Definition.
B. Causes.
A. Recurrent or persistent atelectasis of the right middle lobe.
B. Lymphadenopathy, malignancy.
Type of emphysema associated with
A. Cigarette smokers (2).
B. α₁-Antitrypsin deficiency.
A. Proximal acinar or centrilobular.
B. Panacinar or panlobular.
Types of emphysema associated with bullous disease and idiopathic spontaneous pneumothorax (2).
Distal acinar, paraseptal.
Emphysema: Histology (2).
Alveolar distention without fibrosis.
Club-shaped septa may project into the alveolar spaces.
Interstitial emphysema.
Presence of air outside the airways, e.g. in the connective tissue and around bronchovascular bundles.
Constrictive bronchiolitis: Site.
Terminal conducting airways.
Constrictive bronchiolitis: Associations (8).
Collagen-vascular disease.
Hypersensitivity pneumonitis.
Inhalational injury.
Neuroendocrine hyperplasia/tumors.
Viral infection.
Organ transplantation.
Inflammatory bowel disease.
Drugs.
Constrictive bronchiolitis: Histology (4).
Fibrosis.
Chronic inflammation with epithelial metaplasia.
Smooth-muscle hyperplasia.
Luminal obliteration.
Acute bronchiolitis:
A. Age group.
B. Associations (2).
A. Infants and children.
B. Viral infection, bacterial infection.
Acute bronchiolitis: Histology (3).
Intense acute and chronic inflammation of small bronchioles.
Epithelial necrosis and sloughing.
Edema.
Diffuse bronchiolitis:
A. Epidemiology.
B. Associations (4).
A. Affects Asian adults.
B. HLA Bw54; cold agglutinin, increased ESR, leukocytosis.
Diffuse bronchiolitis: Histology (3).
Lymphocytes, plasma cells, foamy macrophages.
Many intraluminal neutrophils.
Organization of exudate to form polypoid plugs.
Respiratory bronchiolitis: Association.
Cigarette smoking.
Respiratory bronchiolitis: Histology (4).
Interstitial inflammation.
Many intraluminal pigmented macrophages.
Smooth-muscle hypertrophy.
Mild fibrosis.
Mineral-dust bronchiolitis: Type of lung disease.
Restrictive, due to fibrosis.
Mineral-dust bronchiolitis: Histology (3).
Fibrosis.
Deposits of dust mainly around respiratory bronchioles.
Luminal narrowing.
Follicular bronchiolitis: Type of lung disease.
Obstructive, due to external compression.
Follicular bronchiolitis: Histology.
Lymphoid hyperplasia with reactive germinal centers.
Follicular bronchiolitis: Associations.
Anything that causes lymphoid hyperplasia, e.g. chronic inflammation, infections.
Diffuse alveolar damage: Clinical equivalents (3).
Acute respiratory-distress syndrome.
Acute interstitial pneumonia.
Acute lung injury.
Diffuse alveolar damage: Relevance to autoimmune disease (2).
Various collagen-vascular diseases cause DAD-type inflammation.
Various vasculitides can resemble AIP clinically.
Diffuse alveolar damage: Distribution of lesions (2).
Patchy involvement of the lung, but concentrated in the lower lobes.
Diffuse involvement of the alveolus.
Diffuse alveolar damage: Radiography.
Ground-glass opacities that spare the lobules.
Diffuse alveolar damage: Phases.
Exudative: First week.
Proliferative: Second week.
Fibrotic: Late.
Diffuse alveolar damage, exudative phase: Histology.
Hyaline membranes and interstitial edema.
Diffuse alveolar damage, proliferative phase: Histology.
Interstitium and airspaces: Florid proliferation of fibroblasts, myofibroblasts, type 2 pneumocytes.
Arteries: Intimal proliferation, medial hypertrophy.
Diffuse alveolar damage, fibrotic phase: Histology.
Dense interstitial fibrosis with microcysts.
Diffuse alveolar damage vs. usual interstitial pneumonia (3).
UIP:
− No hyaline membranes.
− Temporal heterogeneity of fibrosis.
− Fibrosis has more collagen and fewer cells.
Acute respiratory-distress syndrome: Prognosis.
Most patients regain near-normal lung function.
Acute interstitial pneumonia:
A. Clinical presentation.
B. Prognosis.
A. Resembles severe community-acquired pneumonia but does not respond to antibiotics.
B. Death in 6 months in 78% of cases.
Cryptogenic organizing pneumonia:
A. Clinical presentation.
B. Duration.
A. Cough, dyspnea, and flulike symptoms.
B. Subacute.
Cryptogenic organizing pneumonia: Prognosis.
Usually responds to steroids.
Cryptogenic organizing pneumonia: Distribution of lesions.
Subpleural.
Cryptogenic organizing pneumonia: Radiography.
Peribronchial consolidation and nodularity.
Cryptogenic organizing pneumonia: Histology (2).
Masson bodies: Intraluminal plugs consisting of young fibrous tissue.
Interstitial mild chronic inflammation with foci of foamy macrophages.
Cryptogenic organizing pneumonia: Special stain.
Movat’s stain: Masson bodies appear green; dense fibrosis would appear yellow.
Cryptogenic organizing pneumonia vs. usual interstitial pneumonia.
UIP:
− Dense fibrosis (not seen in COP).
− Fibroblastic foci are interstitial, not intraluminal.
− Temporal heterogeneity of fibrosis.
Cryptogenic organizing pneumonia vs. nonspecific interstitial pneumonia.
NSIP: Interstitial chronic inflammation without Masson bodies.
Usual interstitial pneumonia:
A. Clinical presentation.
B. Duration.
A. Progressive dyspnea and cough.
B. Chronic.
Usual interstitial pneumonia:
A. Associated environmental agents (3).
B. Associated inherited diseases (2).
A. Cigarettes, asbestos, drugs.
B. Familial idiopathic pulmonary fibrosis, Hermansky-Pudlak syndrome.
Usual interstitial pneumonia: Association that imparts a better prognosis.
Collagen-vascular disease.
Usual interstitial pneumonia: Prognosis.
Median survival is 3 years.
Usual interstitial pneumonia: Distribution of lesions (2).
Subpleural.
Lower lobes.
Usual interstitial pneumonia: Radiography (3).
Honeycombing.
Ground-glass opacities.
Traction bronchiectasis.
Usual interstitial pneumonia: Histology.
Temporal heterogeneity: The same area may contain both mature fibrosis and subepithelial young fibrosis (fibroblastic foci).
Spatial heterogeneity: Some areas are affected, some not.
Usual interstitial pneumonia: Histologic findings associated with poor prognosis (4).
Diffuse alveolar damage.
Infection.
Capillaritis.
Organizing pneumonia.
Usual interstitial pneumonia vs. hypersensitivity pneumonitis with fibrosis.
Hypersensitivity pneumonitis:
− Mainly upper lobes.
− Centered on bronchioles.
− More cellular inflammation, including giant cells or poorly formed granulomas.
Usual interstitial pneumonia vs. Langerhans’ cell histiocytosis.
Langerhans’ cell histiocytosis:
− Centered on bronchioles.
− Few or no fibroblastic foci.
Usual interstitial pneumonia: How to diagnose cases that contain findings of other interstitial lung diseases.
As usual interstitial pneumonia.
Nonspecific interstitial pneumonia:
A. Clinical presentation.
B. Duration.
A. Dyspnea, cough, fever.
B. Subacute.
Nonspecific interstitial pneumonia: Associations (5).
Cigarettes.
Drugs.
Immunodeficiency.
Collagen-vascular diseases.
Hypersensitivity pneumonitis.
Nonspecific interstitial pneumonia: Distribution of lesions.
Subpleural.
Lower lobes.
Nonspecific interstitial pneumonia: Radiography.
Peribronchial ground-glass opacities.
Reticular opacities.
Nonspecific interstitial pneumonia: Long-term prognosis.
Cellular type: Excellent.
Fibrotic type: Poor.
Nonspecific interstitial pneumonia, cellular type: Histology (3).
Diffuse interstitial infiltrate of lymphocytes and plasma cells.
Preservation of the pulmonary architecture.
Hyperplasia of type 2 pneumocytes.
Nonspecific interstitial pneumonia, fibrotic type: Histology (4).
Loose to dense interstitial fibrosis that thickens the alveolar walls.
Fibrosis shows temporal homogeneity.
Preservation of the pulmonary architecture.
Mild or moderate chronic inflammation.
Nonspecific interstitial pneumonia: Histological clue to an association.
Abundance of lymphoid aggregates suggests collagen-vascular disease.
Nonspecific interstitial pneumonia: What should not be seen histologically (3).
Significant honeycombing.
Many fibroblastic foci.
Granulomas.
Nonspecific interstitial pneumonia vs. lymphoid interstitial pneumonia.
LIP:
− Denser inflammatory infiltrate.
− Architectural distortion.
Desquamative interstitial pneumonia: Clinical presentation.
Dyspnea, cough, chest pain.
Desquamative interstitial pneumonia: Duration.
Subacute.
Desquamative interstitial pneumonia: Distribution of lesions.
Subpleural.
Desquamative interstitial pneumonia:
A. Frequent association.
B. Infrequent associations (2).
A. Cigarette smoking, even years after cessation.
B. Sirolimus; mutations in SP-C, the gene for surfactant protein C.
Desquamative interstitial pneumonia: Radiography.
Ground-glass opacities.
Thin-walled cysts.
Reticular opacities.
Desquamative interstitial pneumonia: Histology (3).
Pigmented macrophages (originally thought to be “desquamated” pneumocytes) fill alveoli.
Intraalveolar laminated basophilic concretions (“blue bodies”) sometimes present.
No significant fibrosis.
Desquamative interstitial pneumonia: Special stain.
Prussian blue highlights the finely granular pigment within the macrophages.
Desquamative interstitial pneumonia vs. respiratory bronchiolitis-interstitial lung disease.
RB-ILD: Macrophages fill the bronchioles but not the distal airspaces.
Lymphoid interstitial pneumonia: Associations.
Children: AIDS.
Adults: Immunocompromise, including AIDS.
Lymphoid interstitial pneumonia: Clinical presentation in children.
Manifestations of AIDS: Recurrent infections, parotiditis, failure to thrive.
Respiratory failure occasionally.
Lymphoid interstitial pneumonia: Radiography (2).
Children: Miliary reticulonodular infiltrates.
Adults: The same plus alveolar consolidation.
Lymphoid interstitial pneumonia: Histology (2).
Dense mononuclear inflammation of the interstitium, sometimes with germinal centers.
Partial obliteration of architecture.
Lymphoid interstitial pneumonia: Microbiological association.
ISH detects EBV in most cases.
Lymphoid interstitial pneumonia: Clinical course.
No progression to fibrosis.
Hypersensitivity pneumonitis:
A. Associations.
B. Distribution of lesions.
A. Various organic antigens, esp. those of thermophilic actinomycetes and birds.
B. Upper lobes, peribronchiolar.
Hypersensitivity pneumonitis: Phases (3).
Acute: Exposure to high concentrations of antigen; onset in 4-8 hours; resolution in 24-48 hours.
Subacute: Continuous or intermittent exposure to low concentrations of antigen; responds to steroids or to withdrawal of antigen.
Chronic: Subacute plus fibrosis; worse prognosis.
Hypersensitivity pneumonitis, subacute phase: Histology (2).
Small, poorly formed granulomas and mononuclear inflammation next to bronchioles.
Foamy histiocytes in alveoli and interstitium.
Hypersensitivity pneumonitis, chronic phase: Histologic patterns (3).
NSIP-like pattern: Homogeneous fibrosis with architectural preservation.
UIP-like: Patchy subpleural fibrosis with architectural distortion.
Irregular peribronchiolar pattern: UIP-like plus peribronchiolar fibrosis.
Hypersensitivity pneumonitis vs. usual interstitial pneumonia.
UIP:
− No giant cells, no granulomas.
− Mainly subpleural and in lower lobes.
Hypersensitivity pneumonitis vs. nonspecific interstitial pneumonia.
NSIP: No giant cells, no granulomas.
Clinical history may be required to make the distinction.
Hypersensitivity pneumonitis vs. sarcoidosis.
Sarcoidosis:
− Well-formed granulomas with hyalinized rim and location along bronchovascular bundles.
− No UIP- or NSIP-like changes.
Eosinophilic lung diseases: Unknown etiology (3)
Simple eosinophilic pneumonia.
Acute eosinophilic pneumonia.
Chronic eosinophilic pneumonia.
Eosinophilic lung diseases: Known etiology (4).
Allergic bronchopulmonary aspergillosis.
Bronchocentric granulomatosis.
Parasitic infections.
Drugs.
Eosinophilic lung diseases: Vasculitic causes (2).
Allergic angiitis.
Churg-Strauss syndrome.
Eosinophilic lung disease: How to diagnose without tissue or cytology.
Demonstrate pulmonary opacities and peripheral eosinophilia.
Acute eosinophilic pneumonia:
A. Clinical presentation.
B. Associations (2).
A. Acute respiratory distress that mimics infectious pneumonia.
B. Cigarettes, dust.
Acute eosinophilic pneumonia: Histology (3).
Resembles acute phase of DAD but with alveolar and interstitial eosinophils.
Hypertrophied and detached type 2 pneumocytes.
Intact basal lamina.
Acute eosinophilic pneumonia: Prognosis.
Rapid and complete response to corticosteroids.
Acute eosinophilic pneumonia: Degree of eosinophilia.
BAL: More than 25%.
Peripheral blood: Often no eosinophilia at first.
Chronic eosinophilic pneumonia: Radiography.
Peripheral consolidation mainly involving middle and lower zones.
Chronic eosinophilic pneumonia: Laboratory abnormalities (2).
Peripheral eosinophilia.
Elevated IgE in 7% of patients.
Chronic eosinophilic pneumonia: Histology.
Intraalveolar and interstitial eosinophils (single or in aggregates) and eosinophilic giant cells.
Damage to basal lamina, leading to fibrosis.
Parasites that can cause eosinophilic lung disease: Allergic reaction (3).
Entamoeba.
Toxocara.
Clonorchis sinensis.
Parasites that can cause eosinophilic lung disease: Direct invasion (4).
Ascaris lumbricoides.
Ankylostoma duodenale.
Paragonimus westermani.
Schistosomes.
Parasites that can cause eosinophilic lung disease: Others (3).
Strongyloides stercoralis.
Microfilariae.
Dirofilaria immitis.
Sarcoidosis: Frequency of pulmonary disease.
90-95%.
Pulmonary sarcoidosis: Clinical course (2).
Abrupt, acute illness with a better prognosis.
Chronic, insidious illness with persistent, progressive course.
Pulmonary sarcoidosis: Distribution of lesions (3).
Around the lymphatic vessels in the pleura, the interlobular septa, and the bronchovascular bundles.
Histology of pulmonary sarcoidosis:
A. Periphery of granulomas.
B. Tissues involved by granulomas.
A. Concentric fibrosis often; usually no cuff of lymphocytes.
B. Vessels, pleura.
Histology of pulmonary sarcoidosis: Inclusions that can be confused for microorganisms (2).
Hamazaki-Wesenberg bodies: GMS (+), AFB (+); mimic fungi.
Microcalcifications: Mimic fungi or P. jiroveci.
Sarcoidosis vs. hypersensitivity pneumonitis.
Hypersensitivity pneumonitis:
− Granulomas are less well formed.
− More inflammation in the interstitium.
Types of disease associated with a sarcoidosis-like disorder (2).
Malignancies.
Collagen-vascular disorders.
Idiopathic pulmonary hemosiderosis: Age group.
Children and adolescents.
Idiopathic pulmonary hemosiderosis:
A. Clinical manifestations (4).
B. Clinical course.
A. Cough, hemoptysis, iron-deficiency anemia, weight loss.
B. Subject to spontaneous remission or exacerbation.
Idiopathic pulmonary hemosiderosis: Associations (3).
IgA nephropathy.
Dermatitis herpetiformis.
Celiac disease.
Idiopathic pulmonary hemosiderosis: Gross pathology.
Heavy, red-brown lung tissue.
Idiopathic pulmonary hemosiderosis: Histology (2).
Intraalveolar dense groups of hemosiderin-laden macrophages, or frank hemorrhage.
Loss or hyperplasia of alveolar epithelium.
Idiopathic pulmonary hemosiderosis: Pertinent negative findings (5).
Granulomas.
Vasculitis.
Infarction.
Infection.
Immune complexes or immunoglobulins.
Idiopathic pulmonary hemosiderosis: Treatment.
Immunosuppression.
Goodpasture’s syndrome: Relevance of epidemiology to presentation (2).
Young white males: Pulmonary symptoms often precede renal symptoms.
Elderly women: Glomerulonephritis and renal failure precede pulmonary disease.
Goodpasture’s syndrome: Pulmonary manifestation.
Hemoptysis, which may be mild or life-threatening.
Goodpasture’s syndrome: Histology of pulmonary disease (3).
Intraalveolar hemorrhage with many hemosiderin-laden macrophages.
Fibrous thickening of alveolar septa.
Hyperplasia of pneumocytes.
Goodpasture’s syndrome: Ancillary tests (2).
Immunofluorescence: Linear IgG, IgM, or IgA and complement along the alveolar basement membrane.
Serology: Circulating autoantibodies.
Goodpasture’s syndrome: Electron microscopy.
Fragmented capillary basement membranes.
Widened gaps between endothelial cells.
Goodpasture’s syndrome: Antibodies (2).
Anti-GBM against the non-collagenous domain of the α₃ chain of type IV collagen.
Concurrent c-ANCA or p-ANCA in one third of patients.
Goodpasture’s syndrome: Associated HLA type.
DR2.
Pulmonary silicosis: Classification according to timing.
Acute: Symptoms within 3 years after exposure.
Accelerated: Within 3-10 years.
Chronic: At least 20 years.
Pulmonary silicosis: Classification according to gross pathology.
Simple: Nodules up to 1 cm.
Progressive massive: Nodules >1 cm.
Pulmonary silicosis, acute: Histology (3).
Pulmonary edema.
Interstitial inflammation.
PAS-positive granular substance fills alveoli.
Pulmonary silicosis, chronic: Histology.
Discrete fibrous nodules of variable size, mainly in the upper lobes and subpleural regions.
Pulmonary silicosis, chronic: Structure of nodules.
Center: Amorphous.
Middle zone: Layers of dense collagen with focal calcification and necrosis.
Periphery: Particle-laden macrophages, lymphocytes, fibroblasts.
Microbiological association of pulmonary silicosis:
A. Organism.
B. Histology.
A. Mycobacterium tuberculosis (silicotuberculosis).
B. Silicotic nodules with central necrosis and epithelioid granulomas.
Pulmonary silicosis vs. pulmonary alveolar proteinosis.
Pulmonary alveolar proteinosis:
− Little inflammation or fibrosis.
− Protein is reactive for antibodies to surfactant apoptotein.
Pulmonary alveolar proteinosis: Associations (3).
Inorganic dust.
Hematological malignancy.
Immunodeficiency.
Pulmonary alveolar proteinosis: Complication.
Secondary infection by
− Fungi. − Viruses. − Pneumocystis jiroveci. − Nocardia. − Mycobacteria.
Pneumoconiosis: Particles that induce fibrosis (5).
Silica.
Coal dust.
Asbestos.
Beryllium.
Talc.
Pneumoconiosis: Particles that induce little or no fibrosis (3).
Iron oxide.
Tin.
Barium.
Asbestosis:
A. Timing.
B. Clinical presentation (3).
A. Symptoms appear 15-20 years after exposure.
B. Dyspnea, clubbing, restrictive lung disease.
Asbestosis: Location of lesions.
Mostly in the lower lobes.
Asbestosis: How the inhaled fibers get to the pleura.
Through the lymphatic channels (carried in macrophages) or by direct penetration.
Asbestos: Chemical composition.
Hydrated magnesium silicates.
Asbestosis: Appearance of fibers in tissue (2).
Asbestos body: Brown (due to hemosiderin), beaded, two bulbous ends, clear core.
Ferruginous body: No clear core.
Asbestosis: Histology of tissue reaction (3).
Diffuse interstitial fibrosis with chronic inflammation.
Hyperplasia of type 2 pneumocytes.
Alveolar epithelial cells may contain a substance that resembles Mallory’s hyaline.
Asbestosis: Preferred sample for recovery of asbestos bodies.
Bronchioloalveolar lavage.
Asbestosis: Related cancers.
Mesothelioma.
Lung cancer.
Radiation pneumonitis, acute:
A. Timing.
B. Clinical presentation.
A. Symptoms begin between 6 weeks and 6 months after exposure.
B. Cough, dyspnea on exertion.
Radiation pneumonitis: Exacerbating factors (3).
Chemotherapy.
Prior irradiation.
Infection.
Radiation pneumonitis, acute: Histology.
Hyaline membranes as in diffuse alveolar damage.
Interstitial proliferation of atypical fibroblasts within young fibrosis.
Radiation pneumonitis, fibrotic stage: Histology.
Resembles NSIP but with hyperplasia and cytologic atypia of type 2 pneumocytes.
Radiation pneumonitis: Typical cells (2).
Foam cells: Lipid-rich cells with features of macrophages and smooth-muscle cells.
Radiation fibroblasts: Stromal cells with atypical nuclei and much blue cytoplasm.
Radiation pneumonitis: Prognosis (2).
Acute pneumonitis usually responds to corticosteroids.
Carcinoma may arise after >10 years.
Bleomycin toxicity:
A. Incidence.
B. Mechanism.
A. Less than 5%.
B. The lungs are relatively deficient in hydrolase, which detoxifies bleomycin.
Bleomycin toxicity: Exacerbating factors (3).
Oxygen.
Cyclophosphamide and other drugs.
Radiation.
Bleomycin toxicity: Radio-recall phenomenon
Bleomycin can unmask damage to lungs caused by previous irradiation.
Bleomycin toxicity: Histology.
Diffuse alveolar damage.
Atypia of pneumocytes.
Progression to nonuniform fibrosis in some patients.
Amiodarone toxicity: Histology.
Diffuse alveolar damage.
Hyperplasia of type 2 pneumocytes.
Foamy histiocytes in airspaces.
Amiodarone toxicity: Electron microscopy.
Lamellar inclusions in alveolar macrophages.
Methotrexate toxicity: Histology.
Poorly formed granulomas.
Interstitial inflammation that includes eosinophils.
Wegener’s granulomatosis: Clinical triad.
Disease of upper airways (e.g. sinusitis).
Disease of lower airways.
Glomerulonephritis.
Wegener’s granulomatosis: Affected sites (3).
Head and neck.
Lungs.
Kidneys.
Wegener’s granulomatosis: Autoantibody.
c-ANCA in most: Usually against proteinase 3.
Wegener’s granulomatosis in the lungs: Distribution of lesions.
Mostly in the lower lobes.
Wegener’s granulomatosis in the lungs: Gross pathology.
Many nodules of variable size.
Cavitation in half of cases.
Wegener’s granulomatosis in the lungs: Histology (5).
Geographic necrosis.
Granulomatous inflammation.
Palisades of histiocytes.
Microabscesses.
Vasculitis of small vessels.
Wegener’s granulomatosis in the lungs: Special stain.
Elastic stain: Destruction of elastic lamina.
Wegener’s granulomatosis vs. Churg-Strauss syndrome (5).
Churg-Strauss syndrome:
− Eosinophilia in blood and tissues is typical. − Asthma is typical. − Cardiac disease is common. − Renal disease is mild. − Sinus disease is mild.
Churg-Strauss syndrome: Clinical tetrad.
Asthma.
Rhinitis.
Peripheral eosinophilia.
Systemic vasculitis.
Churg-Strauss syndrome: Autoantibody.
p-ANCA in some: Usually against myeloperoxidase.
Churg-Strauss syndrome in the lungs: Gross pathology (4).
Multifocal consolidation.
Eosinophilic pleural effusion.
Stellate peripheral pulmonary arteries.
Cavitation is rare.
Churg-Strauss syndrome in the lungs: Histology (4).
Eosinophilic pneumonia.
Diffuse hemorrhage.
Vasculitis.
Extravascular granulomas with central necrosis.
Churg-Strauss syndrome in the lungs: Pharmacological differential diagnosis.
Carbamazepine-induced vasculitis.
Churg-Strauss syndrome in the lungs: Microbiological differential diagnoses.
Parasitic infection.
Fungal infection.
Pulmonary arterial hypertension: Associations with systemic diseases (4).
Scleroderma.
Sickle-cell disease.
Rheumatoid arthritis.
Systemic lupus erythematosus.
Pulmonary hypertension: Symptoms (5).
Dyspnea.
Chest pain.
Syncope.
Cough.
Hemoptysis is rare.
Pulmonary hypertension: Leading cause.
Left-sided heart failure.
Pulmonary hypertension:
A. Definition.
B. Gross pathology.
A. Pulmonary systolic pressure >25 mmHg.
B. Pulmonary atherosclerosis.
Grading scheme for pulmonary hypertension: Use.
Applies only to idiopathic pulmonary hypertension and to certain types of secondary pulmonary hypertension (“APAH”).
Grading scheme for pulmonary hypertension: Histology of Grade I (2).
Medial hypertrophy of pulmonary arteries.
Extension of muscle into walls of pulmonary arterioles.
Grading scheme for pulmonary hypertension: Histology of Grade II.
Grade I plus proliferation of intimal cells.
Grading scheme for pulmonary hypertension: Histology of Grade III (3).
Grade I plus subendothelial fibrosis.
Small arteries and arterioles: Concentric masses of fibrous tissue, reduplication of elastic lamina, occlusion of vascular lumens.
Large arteries: Atherosclerosis.
Grading scheme for pulmonary hypertension: Histology of Grade IV (3).
Medial hypertrophy is less apparent.
Progressive dilatation of small arteries.
Plexiform lesions.
Grading scheme for pulmonary hypertension: Histology of Grade V (2).
Plexiform and angiomatoid lesions.
Intraalveolar hemosiderin-laden macrophages.
Grading scheme for pulmonary hypertension: Histology of Grade VI (2).
Necrotizing arteritis with thrombosis.
Transmural infiltrates of neutrophils and eosinophils.
Grading scheme for pulmonary hypertension: Which grades are reversible?
Grades I, II, and III.
Grading scheme for pulmonary hypertension: Which grades are associated with secondary pulmonary hypertension?
Grades I, II, and III.
Pulmonary hypertension due to chronic thrombotic or embolic disease: Histology (3).
Little or no medial hypertrophy.
Eccentric intimal fibrosis with focal obliteration.
Organizing thrombi with recanalization.
Pulmonary hypertension: Mutation.
Familial pulmonary arterial hypertension: BMPR4 on 2q33-q34.
Pulmonary veno-occlusive disease: Age group.
Mostly in children and young adults.
Pulmonary veno-occlusive disease: Distribution of lesions.
Pulmonary venules and small veins in the lobular septa.
Pulmonary veno-occlusive disease: Histology of veins.
Occlusion of affected veins by intimal fibrosis.
Medial hypertrophy (“arterialization”) and increase in elastic fibers.
Usually no plexiform lesions or vascular inflammation.
Pulmonary veno-occlusive disease: Additional histology.
Capillaries may be dilated and tortuous, mimicking pulmonary capillary hemangiomatosis.
Hemosiderin may be abundant, mimicking idiopathic pulmonary hemosiderosis.
Pulmonary capillary hemangiomatosis.
Proliferation of capillaries causes thickening of alveolar septa.
CMV pneumonia: Infected cells (4).
Fibroblasts.
Endothelial cells.
Respiratory epithelial cells.
Macrophages.
CMV pneumonia: Effect of ganciclovir on histology.
Makes the intranuclear inclusions redder and rounder.
Herpes simplex virus: Respiratory infections.
Necrotizing tracheobronchitis.
Necrotizing bronchiolocentric pneumonia.
Interstitial pneumonitis resembling DAD.
Measles virus: Respiratory infections.
Necrotizing bronchiolitis.
Giant-cell pneumonia.
Parainfluenza virus:
A. Cytopathic effects.
B. Respiratory infection.
A. None or multinucleate giant cells.
B. Giant-cell pneumonia (genotypes 2 and 3).
Hantavirus:
A. Cytopathic effect.
B. Histology of respiratory infection (2).
A. None; virus is identified by IHC or PCR.
B. Marked alveolar edema; immature leukocytes in alveolar capillaries.
Legionella pneumonia: Type of inflammation (3).
Neutrophilic.
Monocytes and macrophages.
All of the above.
Legionella pneumonia: Other histologic features (3).
Intraalveolar fibrin and hemorrhage.
Abundant nuclear debris.
Vasculitis occasionally.
Legionella pneumonia:
A. Special stain.
B. Other method of detection.
A. Silver stain.
B. Urinary antigen test detects serogroup 1 only.
Nocardia pneumonia: Main route of infection.
Inhalation of bacteria in soil and decaying organic matter.
Nocardia pneumonia: Sites of concurrent infection (4).
Skin.
Bone.
Kidney.
Brain.
Nocardia pneumonia: Histology (3).
Necrosis.
Microabscesses.
Immunocompromised: Poorly formed granulomas rather than abscesses.
Nocardia pneumonia: Special stains (3).
Gram stain.
Fite’s stain.
Silver stain.
Ghon lesion of pulmonary tuberculosis:
A. Size.
B. Consistency.
C. Location.
A. 1-2 cm.
B. Necrotic center.
C. Lower upper lobe or upper lower lobe, near the pleura.
Pulmonary tuberculosis: Ghon complex.
Consists of a Ghon lesion and enlarged hilar lymph nodes.
Pulmonary tuberculosis: Ranke complex.
Fibrosis and calcification of the Ghon complex due to cell-mediated immunity.
Pulmonary tuberculosis: Characteristic cell.
The Langhans cell: A giant cell with peripherally arranged nuclei, formed by the fusion of the histiocytes that surround the granuloma.
Pulmonary tuberculosis: Complications of growth of lesion (4).
Cavitation.
Empyema.
Bronchopneumonia.
Embolization.
Mycobacterium tuberculosis: Virulence factors (3).
Proteins of the cell envelope.
Lipopolysaccharide.
Mycobacterial cell-entry protein (Mcep).
Mycobacterium tuberculosis: Proteins of the cell envelope that impart virulence (3).
Peptidoglycan.
Arabin-galactan.
Mycolic acids.
Mycobacterium tuberculosis:
A. Lipopolysaccharide.
B. Gene for the cell-entry protein.
A. Lipoarabinomannan.
B. mce1A.
Mycobacterium avium complex: Most likely portal of entry.
The gastrointestinal tract.
Atypical mycobacterial infections: Histology (3).
Necrotizing granulomas.
Non-necrotizing granulomas.
Immunocompromised patients: Poorly organized infiltrates of histiocytes, nonspecific inflammation.
Pulmonary disease due to rapidly growing mycobacteria: Leading causes (2).
M. abcessus.
M. fortuitum.
Hyphae of Aspergillus spp.:
A. Branching.
B. Septa.
A. Dichotomous; acute-angle.
B. Frequent.
Hyphae of Fusarium spp.:
A. Branching.
B. Septa.
A. Right-angle mostly.
B. Frequent.
Hyphae of Pseudallescheria boydii.:
A. Branching.
B. Septa.
A. Haphazard.
B. Frequent.
Hyphae of zygomycetes:
A. Branching.
B. Septa.
C. Differences from other fungal hyphae (2).
A. Haphazard; obtuse-angle.
B. Inconspicuous.
C. Wider (up to 25 μm); non-parallel sides.
Zygomycosis: Most common genus.
Rhizopus.
Zygomycosis: Portal of entry.
Inhalation of spores.
Zygomycosis: Predisposing factors (6).
Breach of skin or mucosa.
Iatrogenic immunosuppression.
Neutropenia.
Diabetes mellitus.
Antibiotics, broad-spectrum.
Severe malnutrition.
Zygomycosis: Vascular lesions (2).
Invasion of vessels.
Granulomatous vasculitis.
Growth of zygomycetes in tissue:
A. Facilitating enzyme.
B. Role of iron.
A. Ketone reductase permits growth in acidic, glucose-rich environments.
B. Essential for growth; deferroxamine increases susceptibility to zygomycosis.
Pulmonary aspergillosis: Patterns of disease (3).
Colonization of old cavity lesion (fungus ball).
Hypersensitivity reactions.
Invasion.
Pulmonary aspergillosis: Target lesion.
Necrotic center surrounded by hemorrhagic rim or infarct.
Pulmonary aspergillosis: Classic tissue reaction.
Hemorrhagic infarct with sparse inflammation.
Bronchocentric granulomatosis: Causes.
Infection.
Noninfectious process such as allergy.
Bronchocentric granulomatosis: Histology (2).
Necrotizing granulomatous inflammation destroys small bronchi and bronchioles.
Palisading histiocytes replace the airway walls.
Histoplasmosis: Clinical forms (3).
Acute pulmonary histoplasmosis.
Chronic pulmonary histoplasmosis.
Disseminated histoplasmosis.
Acute pulmonary histoplasmosis: Clinical presentations (2).
Self-limiting illness in a young child with first exposure to H. capsulatum.
Acute, severe illness similar to ARDS, resulting from exposure to a large inoculum of the fungus.
Chronic pulmonary histoplasmosis: Clinical presentation.
Cavitary lesions in an adult with underlying lung disease.
Disseminated histoplasmosis: Risk factors (3).
Infancy.
Immunosuppression.
Congenital T-cell deficiency.
Histoplasmosis: Histology (3).
Necrotizing granulomas with thick fibrous capsule.
Concentric calcification may impart “tree-bark” appearance.
Immunocompromised: Organisms within foamy macrophages.
Pulmonary histoplasmosis: Complications (5).
Granulomatous mediastinitis: Matting and caseous necrosis of mediastinal lymph nodes.
Mediastinal fibrosis: Young adults; often lethal.
Pericarditis, pleural disease, broncholithiasis.
Primary pulmonary coccidioidomycosis: Usual clinical presentation.
Asymptomatic or subclinical; self-limited.
Pulmonary coccidioidomycosis: Cutaneous manifestations (2).
Erythema nodosum.
Erythema multiforme.
Blastomycosis: Initial clinical presentation.
Flulike illness.
Blastomycosis: Histology.
Abscesses at first.
Necrotizing granulomas later.
Disseminated infection: “Yeast lakes” with little inflammation.
Blastomycosis: Radiography.
Can be indistinguishable from primary pulmonary malignancy.
Pulmonary cryptococcosis:
A. Usual clinical presentation.
B. Usual radiography.
A. Asymptomatic.
B. Inapparent.
Pulmonary cryptococcosis:
A. Diagnosis (2).
B. Population at risk for severe disease.
A. Culture or cytology of bronchioloalveolar lavage.
B. Immunocompromised.
Pulmonary cryptococcosis: Gross pathology.
Focal consolidation with gelatinous cut surface.
Pulmonary cryptococcosis: Histopathology in the immunocompetent (2).
Granulomas with fibrosis.
Organisms within giant cells and macrophages.
Pulmonary cryptococcosis: Histopathology in the immunocompromised (3).
Organisms may fill alveoli and cause minimal inflammation.
Dense aggregation of fungi may induce a fibrohistiocytic reaction.
Organisms may lack capsules.
Pneumocystis jiroveci: Four types of infection.
Asymptomatic.
Infantile pneumonia.
Pneumonia in the immunocompromised.
Extrapulmonary infections.
Pneumocystis jiroveci: Risk factors for infantile pneumonia (2).
Malnutrition.
Prematurity.
Pneumocystis jiroveci: Sites of extrapulmonary infection (4).
Bone marrow.
Lymph nodes.
Spleen.
Liver.
Others.
Pneumocystis jiroveci: Radiography.
CT: Bilateral alveolar and interstitial infiltrates radiating from the hilum.
Pneumocystis jiroveci: Life cycle.
Trophozoites conjugate to form cysts, which contain sporozoites, which develop into trophozoites.
Pneumocystis jiroveci: Microscopy of cysts in vivo.
Spherical and contain up to 8 sporozoites that measure 1-2 μm.
Empty cysts resemble cups or helmets.
Pneumocystis jiroveci: Special stains used in identifying cysts (2).
GMS: Best stain; dots within cysts are not sporozoites.
Toluidine blue.
Pneumocystis jiroveci: Special stains used in identifying trophozoites and sporozoites (3).
Wright, Giemsa, and Wright-Giemsa.
Pneumocystis jiroveci: Another stain.
Immunofluorescence: Monoclonal antibody against the wall of the cyst.
Pneumocystis jiroveci: Targets of PCR (4).
Better: Mitochondrial 23S RNA (mtLSUrRNA), internal transcribed spacers.
Others: Cytoplasmic 5S RNA, dihydrofolate reductase regions.
Pneumocystis jiroveci: Peak incidence of pneumonia in children with HIV.
At 3-6 months after delivery.
Lung transplantation: Early complications (5).
Acute rejection.
Bacterial infection.
Pulmonary edema.
ARDS.
Diffuse alveolar hemorrhage.
Acute cellular rejection: Timing.
Usually between 3 and 6 months, but sometimes as early as 1 week or not until years later.
Acute cellular rejection:
A. Incidence.
B. Helpful clinical test.
A. More than 80%.
B. Forced exploratory volume in 1 second (FEV₁) is the most sensitive clinical test.
Criteria of an ideal transbronchial biopsy to be examined for transplant rejection.
At least 3-5 fragments.
At least 100 alveoli and 1 bronchiole.
Acute rejection of lung transplant: Possibly associated histologic finding.
Lymphocytic bronchitis / lymphocytic bronchiolitis.
Chronic rejection of lung transplant:
A. Possibly associated histologic finding.
B. Timing of this finding.
C. Recognition of this finding.
A. Bronchiolitis obliterans (fibrous obliteration).
B. Usually within a year.
C. Pulmonary-function tests; biopsy not required.
Grading of rejection of lung transplants: A0.
No infiltrate of leukocytes.
No hemorrhage.
No necrosis.
Grading of rejection of lung transplants: A1.
Perivascular lymphoid cuff, at least two cell layers thick.
Infiltrate is hard to detect at low power.
Grading of rejection of lung transplants: A2.
Perivascular lymphoid cuff is at least 3 cell layers thick.
No neutrophils, but eosinophils may be seen.
Grading of rejection of lung transplants: A3.
Expansion of lymphoid infiltrate into the interstitium.
Neutrophils may be apparent.
Endothelialitis may be seen.
Grading of rejection of lung transplants: A4.
Diffuse alveolar damage.
Grading of rejection of lung transplants: B0.
No inflammation of airways.
Grading of rejection of lung transplants: B1.
Minimal inflammation of the airways.
Grading of rejection of lung transplants: B2.
Cuff of mononuclear cells, with occasional eosinophils, in the submucosa of bronchi or bronchioles.
Grading of rejection of lung transplants: B3.
Expansion of the infiltrate into a dense band.
Lymphocytic satellitosis with necrosis of epithelial cells of the airway.
Grading of rejection of lung transplants: B4.
Severe inflammation with ulceration of the airway epithelium and fibrinopurulent exudate.
Alveolar adenoma: Histology.
Cystic spaces: Lined by bland type 2 pneumocytes; filled with PAS-positive granular matter.
Stroma: Rich in spindle cells; shows focal myxoid change.
Papillary adenoma of the lung: Histology.
True papillae lined by cuboidal or columnar cells.
Ciliated or oxyphilic cells may be present.
Papillary adenoma of the lung: Which features should be minimal or absent (3)?
Intracellular mucin.
Atypia.
Mitotic activity.
Mucous-gland adenoma:
A. Clinical presentation.
B. Histology.
A. Obstructive symptoms.
B. Bland mucin-producing cells line cysts, glands, microacini, tubules, and papillae.
Mucinous cystadenoma:
A. Size.
B. Histology.
A. 1-5 cm.
B. Cystic spaces lined by incomplete layer of mucinous cells; giant-cell reaction to extravasated mucin.
Bronchogenic squamous dysplasia or squamous-cell carcinoma in situ:
A. Clinical detection.
B. Clinical appearance.
A. Facilitated by autofluorescence bronchoscopy.
B. Flat or superficial (75%); nodular or polypoid (25%).
Bronchogenic squamous-cell carcinoma in situ: Typical location.
Near bifurcations in segmental bronchi.
Bronchogenic squamous dysplasia: Grades.
Mild, moderate, severe.
Bronchogenic severe squamous dysplasia vs. squamous-cell carcinoma in situ.
SCC in situ: Extreme atypia involving full thickness of epithelium.
Basal-cell hyperplasia of the airways: Definition.
Respiratory epithelium with more than three layers of basal cells; otherwise normal.
Squamous-cell carcinoma in situ vs. invasive carcinoma in a transbronchial biopsy:
SCC in situ:
− Smooth edges of the fragments.
− Flat epithelial surface.
− Smooth basement membrane.
Putative order of progression to bronchogenic squamous-cell carcinoma.
Basal cell hyperplasia, squamous metaplasia, squamous dysplasia, SCC in situ, invasive SCC.
Atypical adenomatous hyperplasia: Situation.
Almost always found incidentally in lungs with preexisting adenocarcinoma (invasive or in situ).
Atypical adenomatous hyperplasia: Size.
Up to 5 mm in diameter.
Atypical adenomatous hyperplasia: Histology (3).
Atypical pneumocytes line discrete area of thickened alveolar septa.
Gaps between cells.
Essentially no ciliated or mucous cells.
Atypical adenomatous hyperplasia: Immunohistochemistry.
Demonstrates surfactant protein A (PE10) in up to 25% of cases.
Atypical adenomatous hyperplasia vs. adenocarcinoma in situ (2).
Adenocarcinoma in situ:
− At least 5 mm (usually >10 mm) in diameter.
− May show central collapse with fibrosis or scar.
Atypical adenomatous hyperplasia vs. diffuse interstitial lung disease.
Diffuse interstitial lung disease: Accompanying interstitial inflammation.
Atypical adenomatous hyperplasia vs. peribronchiolar metaplasia.
Peribronchiolar metaplasia consists of ciliated cells.
Atypical adenomatous hyperplasia vs. papillary adenoma.
Atypical adenomatous hyperplasia has no true papillae.
Atypical adenomatous hyperplasia: Mutated genes.
KRAS and EGFR.
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: Histology.
Increase in individual cells or in groups of neuroendocrine cells in the bronchial epithelium.
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: Progression.
Breach of basement membrane to form carcinoid tumorlets.
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: Significance.
May be the precursor of low-grade, peripheral carcinoids.
Carcinoid tumorlet vs. carcinoid tumor.
Carcinoid tumor: More than 5 mm in diameter.
Bronchogenic adenocarcinoma in situ: Former name.
Bronchioloalveolar carcinoma.
Bronchogenic adenocarcinoma in situ: Subtypes.
Nonmucinous (more common).
Mucinous.
Bronchogenic adenocarcinoma in situ: How to report on a biopsy.
As lepidic pattern (could be either adenocarcinoma in situ or invasive adenocarcinoma).
Bronchogenic adenocarcinoma in situ: Mutated genes.
KRAS and EGFR.
Bronchogenic adenocarcinoma: Frequency of metastatic disease at presentation.
About 50%.
Bronchogenic adenocarcinoma: Important feature of gross pathology.
Tumor is usually singular but can be multiple.
Minimally invasive adenocarcinoma of the lung:
A. Definition.
B. Histology.
A. Tumor is no more than 3 cm in size, with an invasive component of no more than 5 mm.
B. Mucinous or nonmucinous.
Bronchogenic adenocarcinoma: Overall importance of growth patterns.
Their percentages should be estimated in the report.
Bronchogenic adenocarcinoma in situ: Histology.
Noninvasive growth of cells along alveolar septa.
No gaps between cells.
Possible slight thickening of septa with desmoplasia.
Bronchogenic adenocarcinoma: Acinar pattern.
Acini and tubules resembling bronchial glands.
Bronchogenic adenocarcinoma: Papillary pattern.
True papillae lined by large, atypical cells.
Papillary may form secondary or tertiary branches.
There may be psammoma bodies.
Bronchogenic adenocarcinoma: Lepidic pattern.
Noninvasive growth along alveolar septa.
Often seen at the edge of an invasive adenocarcinoma.
Bronchogenic adenocarcinoma, solid pattern: Criterion for diagnosis.
At least 5 mucin droplets per 2 high-power fields.
Significance of specific patterns of bronchogenic adenocarcinoma:
A. Solid pattern.
B. Clear-cell pattern.
A. More likely to have the EML4−ALK mutation if there is >10% signet-cell change.
B. If extensive, must be distinguished from renal-cell carcinoma.
Bronchogenic adenocarcinoma: Other patterns.
Micropapillary.
Signet-ring.
Fetal adenocarcinoma of the lung: Histology.
Resembles fetal lung in the pseudoglandular stage; reminiscent of endometrioid adenocarcinoma.
Bronchogenic adenocarcinoma: Helpful immunohistochemical marker.
Napsin A is expressed by pulmonary adenocarcinomas but not by other carcinomas except those of the kidney.
Invasive mucinous adenocarcinoma of the lung: Immunohistochemistry.
Usually negative for TTF-1 and may also lack CK7.
Use of BG8 in immunohistochemistry.
As a marker of epithelial cells; not expressed by mesothelial cells.
Mutations of KRAS in bronchogenic adenocarcinoma:
A. Exons (3).
B. Frequent clinical association.
A. 12, 13, 61.
B. Smoking.
Mutations of EGFR in bronchogenic adenocarcinoma:
A. Exons.
B. Clinical associations (3).
A. 18-21.
B. Female sex; never having smoked; Asian ethnicity.
Bronchogenic adenocarcinoma in situ: Diagnostic criteria (5).
Three of the following:
− Stratification of cells is marked. − Coarse chromatin with large nucleoli. − Height of cells is increased. − Mitotic figures. − Overlap of nuclei due to crowding of cells.
Bronchogenic adenocarcinoma: Mutated genes (3).
KRAS: 30% (most common).
EGFR.
EML4−ALK.
Bronchogenic squamous-cell carcinoma: Variants (5).
Papillary.
Clear-cell.
Small-cell.
Basaloid.
Non-keratinizing.
Bronchogenic squamous-cell carcinoma: Variant associated with a better prognosis.
Papillary variant.
Bronchogenic squamous-cell carcinoma: Histology of the small-cell variant.
Cytoplasm: Moderately abundant; distinct intercellular boundaries.
Nuclei: Irregular; large nucleoli; no molding; no salt-and-pepper chromatin.
Bronchogenic squamous-cell carcinoma: Differential diagnosis of the basaloid variant.
Adenoid-cystic carcinoma:
− Younger patients.
− Better prognosis.
Use of p40 in the immunohistochemistry of lung carcinomas.
Positive in SCC, negative in adenocarcinoma.
Bronchogenic squamous-cell carcinoma: Most common mutation.
Gain of 3q26.
Bronchogenic squamous-cell carcinoma: Important molecular prognostic marker.
Loss of p16INK4A correlates with shorter survival.
Bronchogenic squamous-cell carcinoma: Molecular targets of therapy (4).
PIK3CA, SOX2, DDR2, BRF2.
Small-cell carcinoma of the lung: Consistent mutation.
−3p, which may cause loss of FHIT (fragile histidine triad gene).
Small-cell carcinoma of the lung: Less consistently mutated genes (3).
Bcl-2.
p53.
Rb.
Small-cell carcinoma of the lung: Importance of immunohistochemistry.
The diagnosis of small-cell carcinoma is made by light microscopy, even if all neuroendocrine markers are negative (which occurs in <10% of cases).
Small-cell carcinoma of the lung: Paraneoplastic syndromes (4).
Lambert-Eaton syndrome.
Cerebellar degenerative syndromes.
Cushing’s syndrome.
SIADH.
Large-cell carcinoma: Cytology.
Nuclei: Large, vesicular; large nucleolus.
Cytoplasm: Moderately abundant; discrete cell borders.
Adenocarcinomas of the lung that are usually negative for TTF-1 by immunohistochemistry (3).
Mucinous adenocarcinoma.
Squamous-cell carcinoma.
Large-cell carcinoma.
Large-cell neuroendocrine carcinoma: Histology.
Nuclei: Large nucleolus.
Cytoplasm: Abundant.
Arrangement of cells: Nests, trabeculae, rosettes.
Large-cell neuroendocrine carcinoma: Immunohistochemistry (2,2).
Positive: Cytokeratin, CEA.
Variable: TTF-1.
Staining for neuroendocrine markers is often patchy and weak.
Pulmonary carcinoid tumor: Environmental association.
Atypical carcinoid is associated with smoking.
Pulmonary carcinoid tumor: Sites.
Bronchial (most tumors): May cause obstructive symptoms.
Peripheral: Usually asymptomatic.
Pulmonary carcinoid tumor: Stroma.
Vascular; may contain metaplastic bone or cartilage.
Pulmonary carcinoid tumor: Typical.
> 0.5 cm in diameter.
Fewer than 2 mitotic figures per 10 hpf.
No necrosis.
Pulmonary carcinoid tumor: Atypical.
2-10 mitotic figures per 10 hpf.
- or -
Focal necrosis.
Pulmonary carcinoid tumor: Prognosis (2).
Typical: Five-year survival rate is 90%.
Atypical: Five-year survival rate is 50%.
Expression of neuroendocrine markers by neuroendocrine tumors.
Typical carcinoid: Strong expression.
Atypical carcinoid: Slightly weaker.
Small-cell carcinoma and large-cell neuroendocrine carcinoma: Weakest.
Pulmonary carcinoid tumor: Features that are not used to distinguish typical from atypical tumors (2).
Nuclear atypia and pleomorphism.
Intensity of staining for neuroendocrine markers.
Carcinoid tumors: Positive non-neuroendocrine markers (3).
Cytokeratin.
CD99.
S100 (sustentacular cells).
Pulmonary hamartoma: Typical location.
Peripheral (90%).
Pulmonary hamartoma: Radiography.
Fat and calcification on high-resolution CT.
Pulmonary hamartoma: Histology.
Nodules of mature cartilage, fat, smooth muscle, fibromyxoid tissue, and/or bone.
Benign respiratory epithelium lines the clefts that separate the nodules.
Pulmonary hamartoma: Associated chromosomal regions (2).
12q15 and 6p21: High-mobility-group loci.
Pulmonary hamartoma vs. pulmonary chondroma (2).
Pulmonary chondroma:
− No clefts between nodules.
− Often multiple.
Carney’s triad.
Pulmonary chondromas.
Epithelioid gastrointestinal stromal tumor.
Extraadrenal paraganglioma.
Pulmonary lipoma: Typical site (2).
Within central bronchi.
Left side.
Lymphangioleiomyomatosis: Gender (2).
Sporadic: Females.
Associated with tuberous sclerosis: Both sexes.
Lymphangioleimyomatosis: Clinical behavior.
Destructive and metastatic; considered a low-grade tumor.
Lymphangioleiomyomatosis: Associated tumors (5).
Lymphangioleimyomas of the lungs.
Lymphangioleimyomas of lymph nodes.
Renal angiomyolipomas.
Hamartomas.
Uterine leiomyomas.
Lymphangioleimyomatosis: Clinical presentation (5).
Progressive dyspnea.
Cough.
Chylous pleural effusion.
Recurrent pneumothorax.
Hemoptysis.
Lymphangioleimyomatosis: Gross pathology.
Hyperaerated lungs containing many cysts, 0.5-2 cm, that distort the pleural surface.
Lymphangioleimyomatosis: Types of lesion (2).
Disordered proliferation of smooth-muscle cells near bronchi and vessels.
Air-filled cyst with a wall of disordered smooth muscle.
Lymphangioleimyomatosis: Types of cell (2).
Small spindle cells that express proliferating-cell nuclear antigen.
Larger, epithelioid cells that express HMB-45.
Lymphangioleimyomatosis histology score.
LHS-1: Less than 25% of the lung tissue is replaced by cysts and nodules of LAM.
LHS-2: 25% to 50%.
LHS-3: More than 50%.
Lymphangioleimyomatosis: Immunohistochemistry (4).
Positive: HMB-45, estrogen receptor, bcl-2; D2-40 (often).
Lymphangioleimyomatosis: Abnormal gene, its location, and its product.
TSC2 on 16p13 encodes tuberin.
Lymphangioleimyomatosis: Possible origins of pulmonary lesions.
Migration or metastasis of LAM cells from
- Angiomyolipomas.
- Lymph nodes.
Lymphangioleimyomatosis: Associated tumor of the central nervous system in sporadic cases.
Meningioma.
Inflammatory myofibroblastic tumor: Viral associations (2).
Pulmonary: HHV-8.
Splenic and nodal: EBV.
Inflammatory myofibroblastic tumor: Histology (4).
Fascicles or whorls of spindle cells.
Inflammatory cells.
Variable stroma.
Tumor cells may invade vessel walls and adjacent structures.
Inflammatory myofibroblastic tumor: Cytology (2).
Rare cells may have vesicular nuclei and large nucleoli.
Mitotic figures are usually (but not always) few.
Inflammatory myofibroblastic tumor: Inflammatory component.
Consists of plasma cells, lymphocytes, histiocytes, occasional Touton-type giant cells, granulocytes.
May obscure the spindle cells.
Inflammatory myofibroblastic tumor: Immunohistochemistry (3,3,2).
Positive: Vimentin, SMA, MSA.
Negative: S-100, CD117, myogenin.
ALK and p80 are positive in 45% of cases, more likely in the larger cells with vesicular nuclei.
Inflammatory myofibroblastic tumor vs. inflammatory fibrosarcoma.
Inflammatory fibrosarcoma has more nuclear atypia.
Inflammatory myofibroblastic tumor: Putative cell of origin.
The fibroblastic reticulum cell.
Pleuropulmonary blastoma: Location.
Arises in parenchyma of lung but involves pleura or mediastinum.
Types of pleuropulmonary blastoma: Age groups.
Type I: Infants.
Type II: Toddlers.
Type III: Pre-schoolers.
Type of pleuropulmonary blastoma: Relevance.
Type III has the worst prognosis.
Tumors of type I may progress to type III unless resected.
Types of pleuropulmonary blastoma: Gross pathology.
Type I: Purely cystic.
Type II: Solid and cystic.
Type III: Solid.
Pleuropulmonary blastoma: Cellular components.
Small, blue blastemal cells.
Large, spindle-shaped, often rhabdomyoblastic cells.
No epithelial cells.
Pleuropulmonary blastoma: Histology (3).
Sheets of blastemal cells.
Sarcomatous foci: Malignant cartilage, fat, skeletal muscle, or undifferentiated sarcoma.
Multifocal necrosis.
Pleuropulmonary blastoma: Possibly associated gene.
DICER1, which encodes an endoribonuclease that generates small non-encoding regulatory RNAs.
Pleuropulmonary blastoma vs. metastatic Wilms’ tumor.
Wilms’ tumor: Positive for cytokeratin (epithelial component) and WT-1.
Adult pulmonary blastoma: Epidemiology.
More common in females.
Adult pulmonary blastoma: Histology.
Biphasic, sarcomatoid carcinoma:
− Epithelium: Resembles pseudoglandular stage of fetal lung development (or endometrioid carcinoma with subnuclear or supranuclear vacuoles).
− Stroma: Blastema with occasional sarcomatous differentiation.
Pulmonary MALT lymphoma: Histology (4).
Centrocyte-like monomorphic cells form nodules that infiltrate alveolar septa.
Lymphoepithelial lesions involve bronchial epithelium.
Tumor cells may colonize follicles or mantle zones.
Plasma cells and plasmacytoid lymphocytes may be seen.
Pulmonary MALT lymphoma: Mutations (4).
Trisomy 3.
t(11;18)(q21;q21).
t(14;18)(q32;q21).
t(1;14)(q22;q32).
MALT lymphoma: Frequently involved gene.
JH region of immunoglobulin heavy chain.
Pulmonary MALT lymphoma vs. CLL: Histology.
CLL: Infiltrate does not involve the lung parenchyma.
Pulmonary Langerhans’-cell histiocytosis:
A. Age group.
B. Association.
A. Ages 30-50.
B. Smoking.
Pulmonary Langerhans’-cell histiocytosis: Difference from extrapulmonary LCH.
Pulmonary LCH is a reactive proliferation.
Extrapulmonary LCH is a neoplasm.
Pulmonary Langerhans’-cell histiocytosis: Radiography (2).
Early: Many subcentimeter nodules, esp. in the upper and middle lobes.
Later: Nodules are larger and have central lucency due to cavitation or bronchiolar dilatation.
Pulmonary Langerhans’-cell histiocytosis: Histology (4).
Stellate or Medusa-head nodules centered on bronchioles.
Nodules consist of Langerhans’ cells (grooved nuclei), eosinophils, lymphocytes, plasma cells.
Nodules may invade vessels.
Progression from cellular nodules to fibrotic scars.
Pulmonary Langerhans’-cell histiocytosis: Associated histologic finding.
Respiratory bronchiolitis.
Pulmonary Langerhans’-cell histiocytosis: Expressed cytokines (2).
TGF-β₁.
GM-CSF.
Langerhans’ cells: Immunohistochemistry.
Positive: S-100, CD1a, Langerin.
Negative: CD68.
Reactive eosinophilic pleuritis:
A. Cause.
B. Histology.
A. Pneumothorax.
B. Eosinophils mixed with proliferating mesothelial cells and mononuclear cells.
Post-transplantation lymphoproliferative disorder: Definition.
Abnormal lymphocytic proliferation (benign or malignant) occurring during immunosuppression and often involving the transplanted organ.
Post-transplantation lymphoproliferative disorder: Origin of proliferating cells.
Bone marrow: The donor.
Solid organs: The recipient.
Post-transplantation lymphoproliferative disorder: Timing.
Occurs 1 month to 4 years after the transplantation.
Post-transplantation lymphoproliferative disorder: Viral association.
EBV.
Post-transplantation lymphoproliferative disorder in the lung: Types.
Plasmacytic hyperplasia.
Polymorphic lymphoproliferative disorder.
Malignant lymphoma or multiple myeloma.
PTLD of the lung: Association of type with age.
Plasmacytic hyperplasia is the most common type in children and young adults.
PTLD of the lung: Histology of plasmacytic hyperplasia.
Proliferation of small polyclonal T and B lymphocytes, plasma cells, occasional immunoblasts.
Preserved pulmonary architecture.
PTLD of the lung: Histology of polymorphic lymphoproliferative disorder.
Clonal lymphocytes, plasmacytoid cells; immunoblasts that may resemble Reed-Sternberg cells.
Distorted pulmonary architecture.
PTLD of the lung: Most common type of lymphoma.
Diffuse large B-cell lymphoma.
Post-transplantation lymphoproliferative disorder: Treatment.
Reduction in immunosuppression during the first year after transplantation.
Malignant mesothelioma: Prognosis (2).
Death in <1 year; a few months later for epithelioid mesothelioma.
Malignant mesothelioma: Relation to smoking.
Smoking does not increase the risk of mesothelioma.
Smoking + asbestos = greatly increased risk for lung carcinoma.
Malignant mesothelioma: Variants.
Epithelioid.
Sarcomatoid.
Biphasic.
Epithelioid mesothelioma: Cytology.
Bland, homogeneous.
Nuclei: Round, vesicular; large nucleolus.
Epithelioid mesothelioma: Histology.
Grows in tubules, papillae, glands or acini, solid sheets, or a combination of patterns.
Desmoplastic mesothelioma:
A. Definition.
B. Frequency.
A. A collagenous subtype of sarcomatoid mesothelioma.
B. Makes up about 10% of malignant mesothelioma.
Biphasic mesothelioma: Criterion.
The tumor must be at least 10% epithelioid and at least 10% sarcomatoid.
Malignant mesothelioma: Most common variant.
Epithelioid.
Malignant mesothelioma: “Specific” markers (4).
Calretinin.
CK5/6.
WT-1.
D2-40.
Malignant mesothelioma: Nonspecific markers (2).
Pancytokeratin.
CK7.
Malignant mesothelioma: Mutation.
Homozygous deletion of CDKN2A/ARF at 9p21.
Malignant mesothelioma: Best immunohistochemical marker and its interpretation.
Calretinin:
- Stains cytoplasm of all mesothelial cells.
- Stains nuclei of malignant mesothelioma.
Malignant mesothelioma vs. reactive mesothelial hyperplasia: Histology.
Reactive mesothelial hyperplasia does not invade the parietal pleural fat.
Malignant mesothelioma vs. reactive mesothelial hyperplasia: Immunohistochemistry (4).
Reactive mesothelial hyperplasia: Cytoplasmic desmin.
Malignant mesothelioma: Linear EMA, strong p53, GLUT1.
Desmoplastic mesothelioma vs. chronic fibrosing pleuritis.
Chronic fibrosing pleuritis: Combinations of cytokeratins demonstrate orderly growth and absence of invasion of pleural fat.
Solitary fibrous tumor of the pleura: Histology (3).
Uniform spindle cells in a collagenous stroma.
Alternating hypocellular and hypercellular areas.
Hemangiopericytoma-like vascular pattern.
Solitary fibrous tumor of the pleura: Immunohistochemistry.
Positive: CD34, CD99, bcl-2.
Negative: Cytokeratins (usually).
