This is a gross photo of lung from a fatal case of Wegener granulomatosis. Large necrotizing granulomas are present. A similar appearance might be seen in tuberculous or fungal infections.
Wegener granulomatosis has been reported in patients from 8 to 99 years of age with an average age of 40. It affects men and women with equal frequency and can involve multiple organs. Respiratory tract involvement is characterized by acute necrotizing granulomas of the mucosa and submucosa of the ears, nose, sinuses, and pharynx and/or the lung parenchyma with focal necrotizing and/or granulomatous vasculitis.
This section of lung shows granulomatous inflammation with lymphocytes, epithelioid cells, and giant cells. The involvement is vascular and extravascular.
Upper respiratory tract lesions are mucosal granulomas or ulcerations rimmed by necrotizing granulomas and vasculitis. The vasculitis involves small arteries and veins. The lesions must be differentiated from mycobacterial or fungal infection.
Photo A shows a vessel at higher magnification. Thickening of the wall with chronic inflammation and fibrosis is evident. In photo B one sees extravascular involvement with chronic granulomatous inflammation and abundant giant cells.
WG is probably a form of hypersensitivity. Immune complexes have been demonstrated in glomeruli and vessel walls in some patients. There is a strong association with c-ANCA; granular diffuse cytoplasmic staining for antineutrophil cytoplasmic antibodies.
This microphoto shows a necrotizing granuloma in a case of pulmonary Wegener granulomatosis. Such necrosis is often seen.
Wegener granulomatosis also frequently involves the kidney. Mild renal involvement consists of acute foci of glomerular necrosis. More advanced renal disease takes the form of crescentic glomerulonephritis. Rapidly progressive renal failure may result.
From the slide collection of the late Dr. Charles Kuhn