Pathology of Interstitial Lung Diseases Flashcards
pathologic patterns of interstitial lung disease
diffuse alveolar damage (DAD) - acute
organizing pneumonia (OP) - subacute
usual interstitial pneumonia (UIP) - chronic
non-specific interstitial pneumonia (NSIP) - chronic
granulomatous disease - acute, subacute, or chronic
diffuse alveolar damage
acute lung injury resulting from infections, drug reactions, collagen vascular diseases, vasculitis, aspiration and inhalational injuries, ionizing radiation, pancreatitis, and uremia
early exudative phase and organizing phase
pathogenesis of diffuse alveolar damage
damage to alveolar capillaries and epithelium
increased capillary permeability resulting in interstitial and intra-alveolar edema, fibrin exudation, and hyaline membrane formation
DAD early exudative phase
necrosis of pneumocytes, endothelial cells
hyaline membranes in alveolar ducts
collapse of alveolar parenchyma
organizing phase of DAD
organization of hyaline membranes
formation of airway space granulation tissue
dense collagenization of airway space granuation tissue
specific pathologic findings that point to etiologies in DAD
Infectious organisms (bacteria, viral, fungal, pneumocystis: special stains)
Neutrophils (imply infection)
Eosinophils (Acute eosinophilic pneumonia)
Granulomas (infection, aspiration & drug reaction)
Aspirated food particles (aspiration)
Drug associated changes (foamy macrophages amiodarone; granulomas in methotrexate)
Diffuse hemorrhage & capillaritis (vasculitis)
organizing pneumonia
sub-acute lung injury from any insult
infection
aspiration
drug reactions
minor component of many othe rdiseases cuh as hypersensitivity pneumonitis, NSIP, collagen vascular disease
cryptogenic organizing pneumonia
idiopathic organizing pneumonia
consists of proliferation of granulation tissue within small airways
usual interstitial pneumonia (UIP)
mostly idiopathic
caused by alveolitis, interstitial inflammation, patchy fibrosis with destruction of the underlying lung architecture
can be seen in collagen vascular diseases, drug reactions, familial/genetic disease, chronic hypersensitivity pneumonitis, and pneumoconiosis such as asbestosis
morphology of UIP
thickening of the interstitial wall alternation with normal lung
cobblestoned pleura
patchy fibrosis and traction bronchiectasis
lower lobe and subpleural predominence in the fibrosis
honeycomb lung - end stage lung
complications and causes of death in UIP
carcinoma of the lung
pulmonary hypertension/cor pulmonale
respiratory failure secondary to progressive fibrosis
pulmonary infections
acute exacerbations - acute lung injury superimpose don UIP (50% cause of death)
non-specific interstitial pneumonia
chornic process of hypersensitivity pneumonitis, drug reactions, or collagen vascular diseases
no significant architectural distortion
diffuse mild ot moderate interstitial chornic inflammation with preservation of underlying lung architecture
cellular and fibrotic types
fibrotic has worse prognosis
granulomatous disease
hypersensitivity pneumonitis
fungal and mycobacterial infections
aspiration
berylliosis
drugs
sarcoidosis - idiopathic disease
hypersensitivity pneumonitis
extrinsic allergic alveolitis (EAA)
lung-limited hypersensitivity reaction to an inhaled antigen
known exposure to an offending agent
compatible clinical, radiologic, physiologic findings
BAL with lymphocytosis
symptoms of acute HP
dyspnea, chills, fevers, shortness of breath 4 to 6 hours after exposure, resolves by 48 hours
symptoms of sub acute HP
insiduous onset of SOB oer weeks to months, mild restrctive PFTs, marked lymphocytosis in BAL
symptoms of chronic (fibrotic) HP
insiduous onset of SOP
restrictive PFTs
clubbing sometimes present
features of fibrotic interstitial lung disease on biopsy
old dense fibrosis always present
fibrotic NSIP, UIP like, centrilobular
interstitial, non-necrotizing granulomas, giant cells
histologic features of HP
bilateral ground glass opacities and lobular areas of decreased attenuation and vascularity
interstitial inflammation with lymphocytes and plasma cells surrounding the bronchovascular bundles and extending into the surrounding interstitium
interstitial non-necrotizing granulomas or single giant cells, around bronchioles, in 2/3 cases
histologic features of sarcoidosis
follow lymphatic route in hilar lymph nodes
prominent concentric lamellar fibrosis around granulomas
nodular sarcoidosis
large nodules more than 1 cm in diameter
formed by aggregates of grnulomas
occasionally can show areas of necrosis
berylliosis histology
indistinguishable from sarcoidosis
history of beryllium exposure
beryllium lym lymphocyte transformation testing
aspiration pneumonia histology
organizing pnuemonia
aggregates of histiocytes surrounding food particle
not very well formed granulomas
food particle
presence of individual giant cells or foreign body granulomas
Wegeners Granulomatosis
acute necrotizing granulomas of the upper and lower respiratory tract
acute necrotizing or granulomatous vasculitis of small to medium sized vessels
renal disease - glomerulonephritis
limited wegener’s in the absence of renal disease
pathogenesis is immune mediated
pulmonary eosinophilia
tropical eosinophilia - caused by infection with microfilariae
chronic esoinophilic pneumonia - idiopathic, secondary to infection in association with asthma
pulmonary alveolar proteinosis
unknown etiology - possible overproduction of surfactant by type 2 pneumocytes or its imparied clearance by alveolar macrophages
macrophage dysfunction
alveoli filled with dense, homogenous precipitate without any inflammation
