Review ArticlesMalignant Sweat Gland Tumors An UpdateBrenn, Thomas MD, PhD, FRCPathAuthor Information Department of Pathology, Western General Hospital, The University of Edinburgh, Edinburgh, Scotland The author has no funding or conflicts of interest to disclose. Reprints: Thomas Brenn, MD, PhD, FRCPath, Department of Pathology, Western General Hospital, The University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, Scotland (e-mail: firstname.lastname@example.org). All figures can be viewed online in color at http://www.anatomicpathology.com. Advances in Anatomic Pathology: July 2015 - Volume 22 - Issue 4 - p 242-253 doi: 10.1097/PAP.0000000000000075 Buy Metrics Abstract Sweat gland carcinomas represent an important and somewhat contentious group of tumors in diagnostic skin pathology. Although their overall incidence is rare, they show a wide range of histologic features, and reliable classification is often challenging. Awareness and recognition of these tumors is, however, important as they may be associated with significant morbidity and even disease-related mortality, especially if left untreated. According to their behavior, sweat gland carcinomas are traditionally separated into tumors with low-grade and high-grade malignant behavior. This article is aimed at increasing awareness and providing an overview of malignant sweat gland tumors with emphasis on recently reported and novel findings and diagnostically challenging and potentially underrecognized entities. It further aims to illustrate the wide morphologic range of these tumors and provides a discussion of the relevant immunohistochemistry, disease-specific behavior, and differential diagnosis. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.