Extracranial Metastasis of an Anaplastic Ependymoma, RELA Fusion-Positive: A Rare Occurrence

摘要

Primary intracranial ependymomas originate from ependymal cells. They may migrate mainly in the spinal cord but rarely metastasize outside the central nervous system. Metastases outside the central nervous system are rare. Metastatic diffusion from the central nervous system is low due to the unique interaction of the brain and the tumor with the blood-brain barrier. Nevertheless, three main hypotheses have been mentioned in the literature, the tumor growth, the surgical manipulation (which may be considered to be the case in our patient), and the aggressiveness of the tumor according to the Ki67 index. We report the case of a 16-year-old female, who underwent complete surgical removal of a left occipital 2007 WHO grade II ependymoma. 3 years later, the patient presented multiple cervical and occipital indurated masses. MRI showed a left hemispheric meningeal infiltration, with multiple nodules located on the neck, occiput and mastoid. Histopathological study of a left temporal surgical biopsy and resection of an occipital subcutaneous nodule turned to be metastases of an anaplastic ependymoma. The ependymoma considered as a benign tumor could very quickly turn into malignancy by its metastatic potential. Early diagnosis and longer follow-up of patients would be recommended for a rapid management.