39.    Trichoadenoma of Nikolowsky.
Felipe Mardones, A. Cardemil, H.Fuenzalida, N. Navarrete, F. Schröeder Dermatology Department, University of Chile, Santiago, Chile.

Trichoadenoma of Nikolowsky is a rare, benign and slowly growing tumor with follicular differentiation. It affects adults, mostly in the face or buttocks where it may be present as a solitary nodular or cyst-like lesion. We report a case of a 44 year old female who consulted for a two month old rapidly growing lesion in the left retroauricular region. Clinically, she had a 2 to 3 cm. plaque made up of multiple flesh and yellow colored 3 to 4 mm. papules. Some of the lesions resembled open comedones. The diagnosis of an adnexal tumor was initially proposed, and an incisional biopsy was carried out. Histologically, the tumor was located in the dermis and was made up of multiple and different sized infundibular cysts filled with keratin. Extended strands of basoloid cells were present connecting the cysts. A scarce surrounding stroma was also observed. These findings were consistent with the diagnosis of a trichoadenoma of Nikolowsky. Finally, curettage and electrosurgery of the remaining lesion was performed, with good postoperative results. Trichoadenoma of Nikolowsky was first described in 1958, very few cases are described in the international literature, to our knowledge, this is the first reported case in Chile.