A Case of Cylindroma on the Upper Left Extremity / 대한피부과학회지

Cylindromas are rare benign adnexal tumors that arise primarily on the scalp. There are 2 distinct clinical forms: a solitary form, which is sporadic, and a multiple form, which is dominantly inherited. The lesions are pink-red, nodular, firm, and usually painless, and vary in size. On light microscopic examination, the tumors are nonencapsulated and are located in the upper dermis. They are composed characteristically of aggregations of islands of basaloid cells arranged in a jigsaw pattern and surrounded by hyaline sheaths. Malignant transformation occurs rarely, although some have argued that cylindromas are always benign. We report a man who developed a cylindroma on the upper left extremity, which is an unusual site.