Androgen Receptor Expression Helps to Differentiate Basal Cell Carcinoma from Benign Trichoblastic TumorsIzikson, Leonid MD*; Bhan, Atul MD†‡; Zembowicz, Artur MD, PhD†The American Journal of Dermatopathology: April 2005 - Volume 27 - Issue 2 - p 91-95 doi: 10.1097/01.dad.0000154392.92099.aa Original Article Buy SDC Abstract Author InformationAuthors Article MetricsMetrics Histologic differentiation between basal cell carcinoma and benign trichoblastic neoplasms such as trichoepithelioma and trichoblastoma can be difficult on small biopsies. Therefore, several attempts have been made to identify immunohistochemical differences between these entities. Recent studies have shown androgen receptor expression in a number of mature epithelial structures in the skin and in epithelial neoplasms including basal cell carcinoma. In contrast, androgen receptor expression was absent in mature hair follicles or the few trichogenic neoplasms studied to date. These findings suggested that androgen receptor expression might be a useful adjunct in the histologic differential diagnosis between basal cell carcinoma and benign trichoblastic neoplasms. Therefore, we performed immunohistochemical analysis of androgen receptor expression in 32 basal cell carcinomas and 10 benign trichoblastic tumors (6 trichoepitheliomas and 4 trichoblastomas). In our study, at least focal expression of androgen receptor was detected in 78% of basal cell carcinomas. None of the trichoblastic tumors showed any androgen receptor immunoreactivity. These results confirm the lack of expression of androgen receptor in benign trichoblastic neoplasms and indicate that androgen receptor expression by tumor cells points to basal cell carcinoma as the most likely diagnosis. From the *Department of Dermatology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; †Dermatopathology Unit and ‡Immunopathology Unit, Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. Reprints: Artur Zembowicz, Dermatopathology Unit, Department of Pathology, Massachusetts General Hospital, Warren 820, Boston, MA 02114 (e-mail: firstname.lastname@example.org). © 2005 Lippincott Williams & Wilkins, Inc.