PRIMARY BILIARY CIRRHOSIS is a clinical entity characterized by features associated with interference with intrahepatic bile flow. Frequently, the first symptom is itching, usually followed by jaundice after varying time intervals, which may become severe without conspicuous malaise. Elevation of the serum alkaline phosphatase level, hyperlipemia, and subcutaneous cholesterol deposits are found. Eventually, after many years, manifestations of cirrhosis, such as a portal hypertension, ascites, and hepatocellular failure, appear. The average duration of life after onset of symptoms is about 10 yr.1The anatomic basis of this disease has been described by MacMahon2whereas others have denied the existence of a characteristic pathologic entity.3Therefore, 15 open surgical biopsies, 19 needle aspiration biopsies, and 7 autopsy specimens in cases of primary biliary cirrhosis were studied by conventional microscopy, and biopsy specimens in 10 instances were examined by histochemical, electron microscopic, and immunocytochemical techniques in order to