title: Giant proliferating trichilemmal tumor of the gluteal region.
abstract: 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 x 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.
authors.affiliation: Department of Dermatology, Afyon Kocatepe University, Turkey. skaraca@aku.edu.tr
authors.forename: Semsettin
authors.initials: S
authors.lastname: Karaca
authors.forename: Mustafa
authors.initials: M
authors.lastname: Kulac
authors.forename: Fatma Husniye
authors.initials: FH
authors.lastname: Dilek
authors.forename: Coskun
authors.initials: C
authors.lastname: Polat
authors.forename: Sezgin
authors.initials: S
authors.lastname: Yilmaz
mesh_terms: D000369:Aged, 80 and over; D002081:Buttocks; D005260:Female; D006801:Humans; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery