Cicatricial alopecia secondary to radiation therapy: case report and review of the literature.

Cicatricial or scarring alopecia represents permanent destruction of the hair follicle, histopathologically showing a decreased number of follicular units leaving streamers of fibrosis or hyalinization of surrounding collagen. High-dose radiation therapy (RT) used for treating intracranial malignancy can permanently destroy hair follicles, resulting in permanent alopecia. Typically, there also is clinical scarring of the skin with dermal fibrosis. We report a case of radiation-induced cicatricial alopecia confirmed by histopathology, without obvious clinical scarring or dermal fibrosis. This lack of fibrosis made our patient a good candidate for hair transplantation. The clinicopathologic presentation in this case could be related to the method of RT employed in treating our patient's brain tumor. A literature review of radiation-induced cicatricial alopecia, as well as a brief discussion of the current radiation methods used in the treatment of intracranial malignancy, is presented. We believe that because most anagen follicles are approximately 4 mm deep in the skin, if the dose of radiation superficial to a depth of 5 mm is kept under 16 Gy, which is the approximate lethal dose for hair follicles, the incidence of radiation-induced cicatricial alopecia could be avoided or markedly decreased.