Ultrastructural study of intracytoplasmic deposits in human hepatocellular carcinoma.

Twenty-three cases of human hepatocellular carcinoma were examined electron microscopically, and intracytoplasmic deposits were detected and classified as follow: (1) inclusion bodies such as Mallory bodies, (2) fat droplets, (3) secondary lysosomal changes such as alpha- or beta-glycogen particle accumulations surrounded by a single membrane layer, myelin figure and lipofuscin granules, (4) abnormal changes in organellae such as alpha- or beta-glycogen particle accumulations, the hyperplasia of smooth endoplasmic reticulum, finger prints, glycogen bodies, larger peroxisomes and hypertrophy of bile canaliculus-like structures, (5) degenerative changes in cytoplasm evidenced by debris, focal cytoplasmic degradation and autophagic vacuoles. These intracytoplasmic deposits seem to play important roles in the pathogenesis of hepatocellular carcinoma, but the relation to carcinogenesis is still unclear.