Papillary eccrine adenoma. Light-microscopic, histochemical, and immunohistochemical studies.

In 1977, Rulon and Helwig described 14 cases of a benign sweat gland tumor that they termed papillary eccrine adenoma. These neoplasms have a characteristic morphology, consisting of dilated ducts that contain eosinophilic secretion and are often associated with intraluminal papillations. They also stressed the benign clinical behavior of these neoplasms. Since their original description, occasional single cases have been reported. We describe herein four new cases and their immunohistochemical characteristics, including the presence of cytokeratins, S100 protein, and carcinoembryonic antigen.