Oncocytic hepatocellular carcinoma with numerous globular hyaline bodies

Abstract

Two well circumscribed tumors, oncocytic and non-oncocytic, were removed from the non-cirrhotic liver of a 67 year old male. The large oncocytic tumor (OCT), occupying the entire left lobe, was multilobulated with focal coagulation necrosis and areas of hemorrhage. Light microscopy revealed that it consisted of exclusively large, granular oxyphilic cells with moderate nuclear atypia and occasional mitotic figures, which were trabecular and/or pseudoglandular in structure, but no lamellar fibrosis was seen. Characteristically, the OCT cells included numerous globular hyaline bodies (GHB) of various sizes which were stained red with acid fuchsin and deep blue or magenta with phosphotungstic acid hematoxylin (PTAH), but negative for periodic acid Schiff (PAS), orcein, rhodamine and Grimelius methods. Immunohistochemically, alpha-fetoprotein (AFP), alpha-1-antitrypsin, alpha-1-antichymotrypsin, fibrinogen and ferritin were all negative. On ultrastructural examination, tumor cells were mitochondria-rich, including electron dense, ovoid or polyhedral inclusions, with the delineated membrane identical with that of the GHB. In contrast, the small tumor in the right lobe (Segment 7) was a solid adenoma with no oncocytic transition. Based on these findings, it was postulated that OCT consists of heterogenous proliferation of mitochondria-rich hepatocytes which tend to induce lysosomal GHB closely associated with mitochondrial abnormalities.