Abstract

A 77-year-old Japanese male patient visited us with a 2-year-history of a tender nodule existing at the preauricular portion of the left ear. On physical examination, there was a smooth, brownish, dome-shaped nodule 15×15mm in size with a cratral scab. There were no palpable regional lymph nodes. The lesion was totally excised with more than 1cm safety margin, whose defect was covered by a skin flap made from behind the ear. Histopathological exmanination reveald that a solid feature of BCC adjacent to well differentiated SCC showing marked keratinization. These findings were typical of a collision tumor.