Epidermal cyst is a very common cutaneous lesion. Giant epidermal cyst is defined by its size of more than 5 cm in diameter. Buttock is an unusual site for epidermal cyst. Malignant transformation of epidermal cyst is an exceedingly rare phenomenon. Clinicians should be vigilant of such entity especially in giant epidermal cyst despite a seemingly benign imaging finding. Long term outcome of surgery for such tumor remains an uncertainty.
Ong et al. (Tue,) studied this question.