No ancillary finding is valid to distinguish a primary ovarian hepatoid carcinoma from metastatic hepatocellular carcinoma.

Primary ovarian hepatoid carcinomas (POHC) are extremely rare. Especially rare are those with phenotypic properties of hepatocellular carcinoma (HCC) and an absence of clinical evidence of hepatic tumor. We report a case of a POHC with a common microscopic, immunophenotypic, and ultrastructural property of HCC in the absence of a liver mass. It is extremely difficult to differentiate POHC from metastatic HCC using any kinds of ancillary studies, with the exception of clinical identification of a hepatic tumor.