A 32-year-old man has hemoptysis and hematuria. Urinalysis shows red cell casts. Renal biopsy demonstrates crescentic glomerulonephritis, and immunofluorescence shows linear IgG deposition along the glomerular basement membrane. Serology for antineutrophil cytoplasmic antibodies is negative. The pulmonary lesions in this condition characteristically show:

• A Necrotizing granulomatous inflammation of the upper respiratory tract
• B Hemorrhagic interstitial pneumonitis with antibody deposition on alveolar basement membranes ✓
• C Lymphangitic spread of carcinoma with smooth muscle hyperplasia
• D Caseating granulomas with acid fast bacilli

Explanation

Goodpasture syndrome, now called antiglomerular basement membrane disease, results from antibodies directed against the noncollagenous domain of the alpha-3 chain of type IV collagen, shared by glomerular and alveolar basement membranes. This produces linear IgG staining and pulmonary hemorrhage with hemorrhagic interstitial pneumonitis. Necrotizing granulomas with positive ANCA define granulomatosis with polyangiitis, the key differential in pulmonary renal syndromes.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.