Lymphoepithelioma-like carcinoma of the skin.

We report a case of lymphoepithelioma-like carcinoma of the skin on the right cheek of a 67-year-old man. Histologically, the entire dermis was occupied by multiple lobules of atypical epithelial tumor cell nests surrounded by inflammatory cells. Immunohistochemical examination showed that the epithelial tumor cells were positive for cytokeratin and epithelial membrane antigen. The inflammatory cells were positive for leukocyte common antigen and T-cell marker. Among the tumor nests, small ductal structures were positive for carcinoembryonic antigen. Ultrastructurally, these epithelial tumor cells had well-developed desmosomes and were joined to each other; no tonofilaments were observed in the cytoplasm. These findings strongly suggest that these tumor cells tended to differentiate to the adnexa of the skin.