Chemotherapy of rare skin adnexal tumors: a review of literature.

Malignant skin adnexal tumors are rare neoplasms which are derived from adnexal epithelial structures of the skin: hair follicle, or sebaceous, apocrine or eccrine glands. Among them, eccrine porocarcinoma is the most frequent, with an aggressive behavior compared to other more common forms of non-melanoma skin cancer. Only few reports describe the treatment of metastatic adnexal tumors, and there is no consensus about the better strategy of chemotherapy. Given the few cases and the absence of randomized clinical trials, it is important to collect clinical experiences on these tumors. Most of these adenocarcinomas are very aggressive and also chemoresistant, and only a targeted-therapy could have an impact on patient survival. Therefore, further studies on the biology of these diseases are necessary. The purpose of the present review is to discuss the treatment of malignant neoplasms of cutaneous adnexae and to suggest some future therapeutic options based on targeted-therapy.