Malignant hidroacanthoma simplex. A case report and literature review.

A 73-year-old woman with a malignant hidroacanthoma simplex on her right lower limb is reported. The lesion was immunohistochemically studied. Carcino-embryonic antigen and epithelial membrane antigen were found in the luminal border of ductal structures within the aggregations of neoplastic cells. We review the literature on this subject.