Lung - nontumor
Granulomatous inflammation (noninfectious)
Wegener granulomatosis

Author: Elliot Weisenberg, M.D. (see Authors page)

Revised: 28 February 2017, last major update September 2011

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed search: Wegener granulomatosis [title] lung

Cite this page: Wegener granulomatosis. PathologyOutlines.com website. http://pathologyoutlines.com/topic/lungnontumorwegeners.html. Accessed October 20th, 2017.
Definition / general
  • Triad of necrotizing angiitis, aseptic necrosis of upper respiratory tract and lungs and focal glomerulonephritis
Etiology
  • Likely a T cell mediated hypersensitivity reaction, the close relationship between c-ANCA titers suggests a pathogenic role
  • c-ANCA likely directly activates neutrophils to release oxygen radicals and proteolytic enzymes damaging endothelium
Clinical features
  • May also involve temporal artery, cutaneous small vessels and cause extrapulmonary masses; rarely involves eyes, skin and heart
  • All ages, but most common with ages 45+; more common in males
  • Rarely associated with diffuse pulmonary hemorrhage
  • Should order special stains and cultures to rule out TB and fungi
  • Chest Xray: waxing and waning of pulmonary infiltrates and nodules is relatively specific
  • Diagnosis: biopsy of affected upper airway or skin showing inflammatory change is helpful
  • Limited Wegener’s: confined to lungs, no glomerulonephritis (or occurs many years later), more protracted clinical course; multiple bilateral nodules, round or infarct-like, often in lower lobes; histology similar to classic type, but must have angiitis outside of granulomas and necrotic areas for diagnosis; similar treatment
Laboratory
  • c-ANCA positive in 90% with active generalized disease and 60% with limited disease
  • c-ANCA positive: diffuse cytoplasmic staining directed against neutrophil serine proteinase 3; can monitor course of disease with titers, ELISA test for anti-proteinase 3 now available
  • p-ANCA: perinuclear staining, directed against myeloperoxidase, is usually negative, but positive in microscopic polyarteritis, inflammatory bowel disease, crescentic glomerulonephritis; ELISA test for anti-myeloperoxidase now available
  • Other causes of positive c-ANCA or p-ANCA: connective tissue disorders, chronic hypersensitivity pneumonia, postinfectious bronchitis, ulcerative colitis related lung disease, primary sclerosing cholangitis and rheumatoid arthritis (Mod Pathol 2002;15:197)
Treatment
  • Cyclophosphamide, steroids and TNF-agonists
Clinical images

Images hosted on PathOut server:

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Breast mammogram, courtesy of Dr. Mark R. Wick

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Spot film, breast, courtesy of Dr. Mark R. Wick

Gross description
  • Well circumscribed lesion with necrotic appearance
Microscopic (histologic) description
  • Liquefactive or coagulative necrosis in lungs with profuse eosinophils, multinucleated giant cells, as part of poorly formed granulomas, surrounded by pallisading histiocytes and giant cells with central necrosis
  • Destructive leukocytic angiitis of arteries and veins outside of the necrotic granuloma by neutrophils, plasma cells and eosinophils
  • Scanty lymphocytes and plasma cells
  • Bronchial wall is rarely involved
  • Fulminant subtype has predominance of exudative changes
  • Fibrous scar subtype has marked collagenous stroma
  • Small vessel variant involves alveolar septal capillaries instead of large arteries or veins (resembles SLE)
Microscopic (histologic) images

Images hosted on PathOut server:

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Breast, courtesy of Dr. Mark R. Wick

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Breast, courtesy of Dr. Mark R. Wick



Images hosted on other servers:

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Multinucleated giant cells and chronic inflammation

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Granulomatous inflammation with ill-defined lesions

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Destructive angiitis

Differential diagnosis