Cholestatic jaundice in two patients with primary amyloidosis: ultrastructural findings of the liver.

Two patients with primary amyloidosis (amyloid light chain case) and severe cholestatic jaundice are described. Liver biopsy in the preterminal stage demonstrated amyloid deposits in the perisinusoidal space and in portal tracts, and hepatocytes were atrophic because of compression by amyloid fibrils. Ultrastructural findings showed amyloid fibrils not only in Disse's space but also in the sinusoids, and the hepatocyte microvilli facing the amyloid fibrils were spicular. There were aggregates of lysosomal granules in the vicinity of bile canaliculi and some bile canaliculi were dilated with loss of microvilli. Amyloid fibrils in the portal tract compressed bile ductules, causing wide intercellular space and separated basement membranes from their epitheliums. These findings suggested disturbance in transporting not only of essential materials from sinusoids to hepatocytes but also of secretory vesicles into bile canaliculi and leakage of bile juice from small bile ductules in preterminal stage of primary amyloidosis.