Differentiating Basal Cell Carcinoma from Trichoepithelioma by Using Androgen Receptor Expression

Background: To distinguish a basal cell carcinoma (BCC) from a trichoepithelioma (TE) can be diffi cult even for an experienced dermatopathologist. Objective: In this study, we sought to reconfi rm the androgen receptors (AR) immunostaining pattern of BCC and TE and to determine whether AR immunoreactivity could serve as a useful maker to differentiate these two tumors. Methods: Twenty-one cases of circumscribed BCC, solid type and nineteen cases of TE were obtained from the fi les of the Department of Dermatology, Taiwan. The patients’ medical records were reviewed for the clinical manifestations including age, gender, anatomic sites, color and personal history, especially on the associated AR-related malignancy. The formalin-fi xed, paraffi n-embedded specimens with immunohistochemical staining for androgen receptor expression were surveyed. Results: Our study revealed that AR expression was present in 52.4% circumscribed BCC, solid type. On the other hand, none of the 19 TE samples disclosed any nuclear AR expression. The AR expression in BCC was detected as clusters or scattered individual tumor cells and showed great variations in intensity. In addition, three patients in the AR-positive BCC group had other AR-related malignancies. Conclusion: In conclusion, when we deal with confl icting cases, besides the clinical presentations and the histopathological criteria, AR immunohistochemical staining could give more information for the diagnosis. A positive AR stain could signifi cantly push the diagnosis toward BCC. (Dermatol Sinica 27: 154-160, 2009)