Fourth ventricular ependymoma with a distant intraventricular metastasis: Report of a rare case
A 23-year-old man presented with progressive swaying to either side while walking for five months and progressive headache associated with vomiting for four months prior to presentation. There was no history of seizures, diplopia or similar illness in family members. Examination revealed bilateral papilloedema and bilateral cerebellar signs. The patient was initially evaluated by a general practitioner at local hospital with computed tomography (CT) of the head. It revealed a midline posterior fossa mass lesion, isodense on non-contrast CT and enhancing heterogeneously on contrast injection with obstructive hydrocephalus. He was subsequently referred to our hospital. The patient was first seen at our hospital two months after the initial CT scan. Magnetic Resonance Imaging (MRI) of the brain done about 2 months after initial CT showed increase in the size of the tumor which was isointense on T1WI and T2WI and enhancing heterogeneously on gadolinium contrast injection. The lesion was completely intra-fourth ventricular []. Another lesion was noted in the septum pellucidum extending to the frontal horn of the left lateral ventricle causing obstruction of the foramen of Monro on the left side []. It had the same signal characteristics as that of the tumor. This lesion was not present in the initial CT scan [], which was done two months prior to the MRI. There were no other lesions seen on craniospinal MRI.\nIn view of severe symptoms of raised intracranial pressure, he initially underwent ventriculo-peritoneal shunt placement followed by midline sub-occipital craniectomy and near total excision of the tumor except for the part adherent to the brainstem. Post-operatively, he recovered well.\nHistopathological examination showed a cellular glial neoplasm consisting of proliferating ependymal cells arranged in compact sheets and several intervening perivascular rosettes. The cells exhibited brisk mitotic activity (6 to 7 in 10 high power fields) with areas of necrosis []. These features suggested a diagnosis of anaplastic ependymoma (grade III).\nThe patient was subsequently referred to radiation oncologist for adjuvant therapy.