A light microscopic and ultrastructural study of spindle-shaped hepatocellular carcinoma.

Spindle-cell hepatocellular carcinoma is an unusual morphologic variant of hepatocellular carcinoma with a typical sarcomatous appearance. The exact diagnosis of this tumor may be difficult when only small biopsies are available and in the absence of ultrastructural studies. We describe two cases of hepatocellular carcinoma: one was entirely composed of spindle-shaped cells, and the other was a typical hepatocellular carcinoma with only a small area of sarcomatous, fusiform cells. In the first case, ultrastructural studies demonstrated desmosomes and many Mallory bodies and confirmed the epithelial nature of the neoplasm. In the second case, no ultrastructural studies were available, but the presence of gradual transition from liver cell carcinoma to spindle-cell carcinoma excluded the diagnosis of carcino-sarcoma.