Abstract

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.