Squamous cell carcinoma arising in a cutaneous epidermal cyst--a case report.
BACKGROUND
Cutaneous epidermal cysts are common lesions, but fortunately, malignant transformation of their epithelium is rare. There are only a few cases mentioned in recent literature, mostly occurring in epidermal cysts in the head and neck region.


METHODS
We present a case of malignant transformation in a long-standing buttock epidermal cyst, presenting a month after trauma to the cyst.


METHODS
An excision biopsy and rotation flap was done. When the pathology was confirmed, a second resection was carried out and the defect covered with a free latissimus dorsi flap, a buttock rotation flap and a posterior thigh rotation flap.


CONCLUSIONS
Although malignant transformation is rare, this case illustrates the importance of routine histology in excision of epidermal cysts.
Department of Plastic Surgery, Singapore General Hospital, 1 Hospital Drive, Singapore 169608.
T H
TH
Wong
A K
AK
Khoo
P H
PH
Tan
B H
BH
Ong
D001706:Biopsy; D002081:Buttocks; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D004814:Epidermal Cyst / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D013524:Surgical Flaps; D016896:Treatment Outcome