A case of epidermotropic metastatic mammary carcinoma

A special type of metastatic carcinoma to the skin, epidermotropic carcinoma, is thought to be a parasitic occupation of malignant tumors in the epidermis. A patient, a 56-year-old Japanese woman who had had a mastectomy because of mammary carcinoma thirteen months earlier, developed a metastatic skin tumor in the operation wound and another area of mammary skin. Histologically, almost only the epidermis was occupied by multifocal metastatic tumor nests, so the tumor was a type of epidermotropic metastatic carcinoma. Moreover, some tumor nests were found to be eliminated from the epidermis. Like other types of metastatic skin tumor, nevus pigmentosus, and amyloidosis, epidermotropic metastatic carcinoma can show transepithelial elimination.