Giant Proliferating Trichilemmal Tumor of the Gluteal Region

Background. Proliferating trichilemmal tumors are rare cutaneous neoplasms that show features of typical pilar cysts but also show extensive epithelial proliferation, variable cytologic atypia, and mitotic activity. Proliferating trichilemmal tumors are benign lesions; however, there are numerous reports of malignant proliferating trichilemmal tumors. Objective. We present a case of benign proliferating trichilemmal tumor of an 81-year-old woman that was located on the left superior gluteal region for 30 years. Methods. A tumor measuring 9 × 7 cm was surgically excised with a 1 cm conservative margin of normal tissue. Results. Based on the histopathologic findings of tumor, this case was diagnosed as proliferating trichilemmal tumor. The patient's condition was successfully treated with total excision. Conclusions. Our case is an unusual presentation of proliferating trichilemmal tumor. Physicians should be aware of this entity while differentiating cutaneous tumor located on the gluteal region. SEMSETTIN KARACA, MD, MUSTAFA KULAC, FATMA HUSNIYE DILEK, COSKUN POLAT, AND SEZGIN YILMAZ HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.