Skin adnexal neoplasm closely resembling adenomatoid tumor: a unique occurrence

We describe a primary skin neoplasm located in the left chest wall that closely resembled adenomatoid tumor of male and female genital tract. It occurred in a 52-year-old woman who had undergone a left quadrantectomy with regional lymphadenectomy for invasive ductal carcinoma of the breast 7 years previously. The tumor involved the dermis and subcutaneous tissue and measured 0.7 cm in greatest diameter. Immunohistochemical evaluation showed strong positivity for cytokeratin pool and negativity for CD31, calretinin, WT-180, and for estrogen and progesterone receptors. We are unaware of a previous description of this morphologic pattern in a primary skin tumor, which we have interpreted as of skin adnexal and specifically of eccrine sweat gland origin.