[Unusual ultrastructural findings in a case of asymptomatic primary biliary cirrhosis].

The investigators report an ultrastructural study of a case of primary biliary cirrhosis histologically in stage II (Scheuer), a rare disease which has not been investigated extensively at the ultrastructural level. Biliary canaliculi are dilated and microvilli are scarce. Large granular formations are observed in the perisinusoidal cytoplasm. The plasma membrane between adjacent hepatocytes appears convoluted. The ultrastructural alterations of the biliary canaliculi which we observed have been described in the literature in cholestatic patients and ascribed to cholestasis. Our patients, however, has never suffered episodes of jaundice or itching and has no histological signs indicating cholestasis. We suggest that these are precocious alterations which precede the appearance of clinical and histological signs of cholestasis. It is necessary to study other cases in order to evaluate the significance of the large granular formations and the changes observed in the plasma membrane.