Sweat Gland Tumors – A Systematic Review on the Histopathology and Immunohistochemistry

Abstract

Objective: The categorization of sweat gland tumors has been inconsistent over time. These tumors, having varying potential for malignancy, may behave as indolent neoplasms while others can be highly metastatic. The characteristics of most of these tumors are overlapping and the information of distinctive findings about these neoplasms is imperative. Traditionally, sweat gland tumors were classified as eccrine and apocrine only but recently, this has been found that several sweat gland tumors may exhibit eccrine and apocrine types both. Some tumors exhibit further complex features due to the existence of other differential appearances. This can be in the instance of apocrine neoplasms because of the close embryological link between apocrine glands, hair follicles and sebaceous glands and they can be classified as follicular and/or sebaceous tumors. Cutaneous adnexal neoplasms are a diagnostic challenge, especially for tumors with sweat gland differentiation, due to a huge number of uncommon entities, designation of different terms to the identical tumor following to disagreement about the taxonomy and nomenclature of such tumors. This review article provides updated information about various cancerous sweat gland neoplasms with emphasis on recent conclusions for the diagnosis and generalized therapy of such neoplasms.