An unusual apocrine carcinoma on the forehead.

We herein report an unusual case of apocrine carcinoma on the forehead. The lesion was formed by the anastomosis of numerous tubular structures with widespread decapitation secretion, thus demonstrating apocrine differentiation. However, we observed some unusual histopathologic features that differed from those found in typical examples of apocrine ductal carcinoma, namely: 1) a relatively well-circumscribed lesion in the dermis, and 2) nodular or solid aggregations composed of basaloid cells. We believe the present case is an apocrine ductal carcinoma, although it has a nodular appearance and basaloid cells. Otherwise, it could be a hitherto undescribed variant of apocrine carcinoma. This apocrine carcinoma on the forehead may have originated from either pluripotential cells or from apocrine glands at an unusual site.