Anaplastic ependymoma metastases to the scalp requiring free flap surgeryendymoma metastases to the scalp requiring free flap surgery

Abstract

Ependymomas are glial central nervous system tumors that derive from the ependymal lining of the ventricular system or central canal of the spinal cord. They may occur anywhere along the neuraxis, but most commonly in the posterior fossa in the floor of the fourth ventricle and in the location of the conus medullaris, cauda equina and filum terminale. According to the World Health Organization (WHO) classification ependymomas are divided into four groups on the basis of their histologic appearance: myxopapillary ependymoma; subependymoma (WHO grade I); ependymoma with cellular, papillary, clear cell and tanycytic variants (WHO grade II); anaplastic ependymoma (WHO grade III). Anaplastic ependymomas are characterized by increased cellularity, cytological atypia, mitotic figures, vascular proliferation and areas of necrosis. Ependymomas, including the anaplastic type, have the potential to spread via the cerebrospinal fluid pathways; nevertheless intraspinal dissemination or metastasis of fourth ventricle tumor is a rare condition. The incidence is higher with higher WHO grade. Intracranial and spinal ependymomas frequently relapse at the primary site in case of incomplete surgical removal. For this reason, gross total resection followed by craniospinal radiation therapy is the treatment of choice. The extremely rare presence of metastases outside the central nervous system and even primary extraneural ependymomas were reported in the literature. Herein, we describe an unusual case of extraneural metastases of supratentorial anaplastic ependymoma with its treatment history.