Primary mucinous carcinoma of the skin

Abstract

A 41-year-old man complained of a tumor on his right malar region for two years. Physical examination showed a firm, skin-colored, movable nodule measured 1 cm in diameter. He felt no subjective symptoms. Histopathological examination showed that there was abundant mucin in the dermis which was separated by fibrous septa. Fat was involved in the tumor. Some agglomerate epithelial cells, with glandular differentiation, were floating in the background of mucin. There were a few mitotic figures. Immunohistochemical results revealed the tumor cells were stained positive for CK7, and negative for CDX2, Villin, TTF1, CK20 and PSA. He was diagnosed as primary mucinous carcinoma of the skin according to histopathological and immunohistochemical characters.