8407/3 Sclerosing sweat duct carcinoma


Syringomatous carcinoma
Microcystic adnexal carcinoma


ICD-O-3 topography code: C44
ICD10: C44

Microcystic adnexal carcinoma (MAC) is a slow-growing, low grade adenocarcinoma with ductal differentiation arising from the sweat glands. It is locally infiltrative and destructive. Tumour cells are well differentiated and lack nuclear polymorphism or mitotic figures. Histologically, the lesion appears stratified. On the surface, it consists of small, solid to cystic structures that resemble infundibular cysts and ducts. The middle area is composed completely of small ducts and frequently involves nerves and perineural spaces. In the deepest area, sclerosis and epithelial cords are common observations. MAC most commonly arises on the face and lip. Its appearance is similar to a scar. Ulceration is rare.
Microcystic adnexal carcinoma affects adults, with a predilection for women. Treatment of choice is surgical excision. Metastatic spread is rare1
LeBoit PE, Burg G, Weedon D, Sarasin A (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Skin Tumours
3rd Edition
IARC Press: Lyon 2005