ADENOID CYSTIC SWEAT GLAND CARCINOMA - A CLINICOPATHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY

Adenoid cystic carcinoma of the skin is one of the rarest sweat gland tumours. We have studied two cases of adenoid cystic sweat gland carci noma clinically, histologically and immunohistochemically. One tumour was located on the occiput of an 18-year-old male patient, while the o ther developed on the back of a 49-year-old woman. Histologically, bot h carcinomas were characterized by basaloid tumour cells showing the t ypical adenoid-cystic growth pattern. The cells were arranged in solid , cribriform, tubular and cystic aggregates, which were surrounded by mucoid, Alcian blue material. Immunohistochemically, the tumour cells showed coexpression of cytokeratins typical of stratified epithelia (C K1/5/10/14) and cytokeratins of the simple epithelial type, namely CK7 , CK8, CK18, and CK19. Coexpression of these cytokeratins is usually o bserved in normal fetal sweat glands, but not in adult sweat glands.