Granulomas of the Liver

Hepatic granulomas are found in 1-6% of liver biopsy and surgical specimens globally, generally reflecting the local prevalence of disease processes. Worldwide, tuberculosis and sarcoidosis are the most common etiologies, with primary biliary cholangitis, schistosomiasis, brucellosis, Q fever, and viral hepatitis B and C also frequently reported. More than 50 drugs are associated with granulomas, the most common being allopurinol, sulfonamides, phenylbutazone, and phenothiazines. Of granuloma cases, 10-20% remain idiopathic, with no specific cause identified. Two main types are recognized histologically: epithelioid granulomas are the predominant form, with necrotizing features often reflecting an infectious etiology; lipogranulomas are associated with ingestion of mineral oil or lipids contained in foodstuffs. Fibrin-ring granuloma, a distinctive form of lipogranuloma, is associated most often with Q fever and allopurinol hypersensitivity. Granulomatous hepatitis may be a feature of fever of unknown origin. Treatment of hepatic granulomas is directed at the specific infectious or inflammatory etiology. Drug-induced causes often resolve spontaneously.