Atypical presentation of hepatocellular carcinoma.

Hepatocellular carcinoma is relatively rare in the United States, and the patterns of extrahepatic manifestations are diverse. Disease dissemination occurs through hematogenous routes to frequently involve the lungs, bone, adrenal glands, and pancreas. Soft tissue metastasis is extremely rare and mandates systematic pathologic analysis, which may include the use of immunohistochemical staining for tumor-specific markers. Relevant tumor markers that can assist in localizing the site of origin for adenocarcinoma include carcinoembryonic antigen, alpha-fetoprotein, vimentin, and anticytokeratins. We detail the utility of immunohistochemistry in evaluating tumors of unknown origin.