Bilaterally symmetrical epidermal inclusion cysts with foreign-body giant-cell reaction.

Epidermal inclusion cysts often occur as a result of traumatic implantation of epidermal cells into dermal tissue. The epidermal cells within the dermis can continue to grow and lead to the production of a lipid- and keratin-filled cyst, which can erode into bone and adjacent tissues. The authors present a case of bilaterally symmetrical epidermal inclusion cysts that occurred separately over a 10-year period. A brief review of the literature is also presented.