Basal cell carcinoma at the base of cutaneous horn (cornu cutaneum).

To the Editor.— In daily clinical work and the dermatopathological literature, cutaneous horns are identified with the histological diagnosis of senile (solar) keratosis, with eventual malignant transformation into squamous cell carcinoma. Basal cell carcinoma at the base of a cutaneous horn is an infrequent finding. Report of a Case A 58-year-old woman was referred to our department because of a horny tumor on her right cheek which had appeared some five years before, progressively becoming larger. She had never consulted anyone for this tumor. Examination: The patient had fair skin and hair and blue eyes. A few foci of solar keratosis were dispersed over her forehead, nose, and upper lip. On her right cheek there was a horny, curved tumor measuring 1.8 cm in length. The base of the tumor, which was 7 mm in diameter and 4 mm in height, was fleshy and the same color of the skin,