The role of granulomatous phlebitis and thrombosis in the pathogenesis of cirrhosis and portal hypertension in sarcoidosis

Sarcoidosis often involves the liver with mild elevation of serum enzymes and granulomas histologically. Rarely, chronic cholestasis, portal hypertension, cirrhosis, or nodular hyperplasia may be found. The pathogenesis of the portal hypertension and of the cirrhosis are not understood, in part because large samples of tissue have seldom been described. We describe the clinical and anatomic findings of four patients with sarcoid liver disease in whom the whole livers were available for examination. One patient had cirrhosis, one had diffuse nodular hyperplasia, and two had small regions of parenchymal fibrosis. The first two of these had a history of variceal bleeding and healed portal vein thrombosis. One had chronic cholestasis without cirrhosis. We suggest that the cirrhosis and focal fibrosis were caused by ischemia secondary to primary granulomatous phlebitis of portal and hepatic veins. The portal hypertension in two patients was likely secondary to portal vein thrombosis, because cirrhosis was absent at the onset of variceal bleeding.