A Case of a Tumor of the Follicular Infundibulum-like Change in Nevus Sebaceus

Baik, Yong Gwan; Park, Sung Ju; Min, Hyung Geun; Lee, Ho Gyun; Kim, Jong Min

Abstract

Cribier and Grosshans(1995) reported two cases of tumor of the follicular infundibulum(TFI) arising in nevus sebaceus for the first time. In 1961 Mehregan and Butler described a new benign adnexal neoplasm, which they called tumor of the follicular infundi4ulurn." Since then few observations have been published. The majority of the lesions are solitary. They appeared in adults, predominantly in wornen, on the face, arm, and neck. Histopathologically, the unique feature is a benign hyperplastic lesion that extends from the follicular infundibuluni. as an epithelial plate either with underlying elastic fiber network in TFI or without underlying elastic fiber network in TFI like change. A 52-year-old man has haf a solitary, well-defined, hairless, verrucous plaque on his right supra auricular area for about 10 years. It has seerned to increase gradually in size over the last year. The histologic findings shwed a plate-like growth of epithelial cells in the upper dermis extending parallel to the epidermis with multiple connections at the lower margin of the epidermis. The peripheral cell layer of ttie tumor plate showed palisading, and centrally located cells were pale staining. Many hair follicl s, mature sebaceous glands, ectopic apocrine glands, and inflammatory cell infiltrations were present in the dermis. However, there was no elastic fiber network beneath the epithelial cell plate. We believe our case is the first to be reported in Korea as TFI-like change in nevus sebaceus.