Malignant change in an intradiploic epidermoid: report of a case and review of the literature.

An unusual case of intradiploic epidermoid tumor is reported. In this case, a soft mass located over the parietal bone was noted shortly after birth. The mass gradually enlarged. The tumor underwent malignant change after several excisions and repeated inflammations. The patient was successfully treated with extensive excision, radiotherapy, and chemotherapy. Compiling a summary of reported cases with a tabulation of pertinent information, we discuss the incidence, pathogenesis, prognosis, and therapy of malignant intradiploic epidermoid.