Metastatic hepatocellular carcinoma of skin diagnosed with hepatocyte paraffin 1 and a-fetoprotein immunostainings.

A rare case of skin metastasis of hepatocellular carcinoma diagnosed with an aid of immunohistochemical stainings of hepatocyte paraffin 1 and a-fetoprotein is reported in this study. An 86-year-old Japanese man was admitted to our hospital due to cutaneous mass in the right chest. An incisional biopsy was performed, which showed proliferation of malignant cells with eosinophilic or clear cytoplasm arranged in solid nests. No trabecular pattern was recognized. Sebaceous carcinoma, clear cell sarcoma, malignant granular cell tumor, metastatic renal cell carcinoma, and metastatic hepatocellular carcinoma were suspected on hematoxylin and eosin preparations. An immunohistochemical study showed that the tumor cells were positive for cytokeratins, hepatocyte paraffin 1, and a-fetoprotein but negative for vimentin, desmin, a-smooth muscle actin, S-100 protein, epithelial membrane antigen, carcinoembryonic antigen, chromogranin, neuron-specific enolase, CD10, CD30, CD34, CD45, CD68, and HMB45. Metastatic hepatocellular carcinoma of the skin was diagnosed pathologically. This case suggests that skin tumors with eosinophilic cytoplasm should be examined by hepatocyte paraffin 1 and a-fetoprotein.