[Giant trichilemmal carcinoma of the retroauricular: a case report].

The trichilemmal carcinoma is a rare tumor that usually occurs on sun-exposed skin, especially on the face, scalp, neck and back of hands, mainly in elderly subjects but commonly between the 4th and 9th decades of life. We report a case of giant trichilemmal carcinoma. A 65-year-old man presented with a 5-year history of a slowly developing mass arising from his right retroauricular region, with local destruction of the auricle. The lesion appeared as a 8.0 cm×6.5 cm×2.0 cm sized, with surface ulceration and erosion, subcutaneous nodule, and mild tenderness. Preoperative pathological biopsy showed: "retroauricular" trichilemmal carcinoma. The patient underwent right retroauricular tumor resection, partial auriculectomy, neck adjacent skin flap repair and auricle reconstruction. Postoperative pathological report: "retroauricular" trichilemmal carcinoma. The margin of incision was negative, and the lymph nodes in zone II were negative. Immunohistochemistry: Tumor cells were CK5/6（++）, p63（++）, p40（++）, CD10（-）, EMA（-）, Ki-67（+, about 60%）.