Extradural sacrococcygeal subcutaneous ependymoma misdiagnosed as pilonidal disease: case report and review of the literature.

Ependymoma is a type of glial tumor that arises from the ependymal lining of the ventricular system of the central nervous system. These tumors may present as a rare extraspinal variety at the sacrococcygeal region, and may be misdiagnosed as pilonidal disease in the post-sacral area or present with mass-effect symptoms on the bowel or bladder in the pre-sacral region. This is a case of soft tissue swelling at the post-sacral area that, after clinical examination, was diagnosed as pilonidal disease. Surgical excision and pathologic examination revealed a subcutaneous sacrococcygeal ependymoma.