Ectopic hepatocellular carcinoma, an unexpected diagnosis of a retroperitoneal mass: A case report and literature review.

Ectopic hepatocellular carcinoma (HCC) is defined as HCC arising from hepatic parenchyma located in an extrahepatic organ or tissue without any communication with the mother liver. It is very rare and difficult to diagnose by imaging alone. We report a case of a rare ectopic HCC mimicking a right para-aortic retroperitoneal mass and present a review of the literature. It is about a 79-year-old female patient, who presented with a progressive enlarged right paraaortic retroperitoneal mass, thought first to be leiomyosarcoma of vena cava on imaging. Subsequently, high alpha-fetoprotein (AFP) level and biopsy allowed the diagnosis of primary extrahepatic hepatocellular carcinoma.