Hepatocellular Carcinoma with Cervical Spine and Pelvic Bone Metastases Presenting as Unknown Primary Neoplasm.

The occurrence of hepatocellular carcinoma (HCC) is closely associated with viral hepatitis or alcoholic hepatitis. Although active surveillance is ongoing in Korea, advanced or metastatic HCC is found at initial presentation in many patients. Metastatic HCC presents with a hypervascular intrahepatic tumor and extrahepatic lesions such as lung or lymph node metastases. Cases of HCC presenting as carcinoma of unknown primary have been rarely reported. The authors experienced a case of metastatic HCC in a patient who presented with a metastatic bone lesion but no primary intrahepatic tumor. This case suggests that HCC should be considered as a differential diagnosis when evaluating the primary origin of metastatic carcinoma.