A case report of a patient with an anaplastic oligodendroglioma confined entirely within the ventricular system is presented. The patient underwent gross total surgical resection with perioperative shunt placement, yet developed aggressive recurrence of disease. The literature regarding the clinical presentation, methodology of diagnosis, and treatment of IVO was reviewed. Thirty-three studies reporting 70 patients with IVO were identified in the literature. Only 2 previous case reports of high-grade/anaplastic IVO were identified. Accurate diagnosis of these lesions, including immunohistochemistry, electron microscopy, and molecular/chromosomal subtyping, is imperative. Surgical resection with frequent perioperative shunting, as well as chemotherapy, remains the mainstay of therapy. Adjuvant therapies may differ significantly according to the tumor grade and molecular subtype.

Intraventricular oligodendroglioma remains an infrequently encountered lesion, yet is usually found to be low grade at the time of surgery. Anaplastic IVO is an exceedingly rare lesion, with only 3 case reports in the literature. Future therapy for these aggressive lesions may be based on susceptibility to various chemotherapeutic agents according to molecular sub typing ¹⁾.

Metastatic involvement of the cerebro-spinal fluid (CSF) pathway in oligodendrogliomas is not uncommon; however, symptomatic involvement of the spinal cord is very rare: less of 10 cases have been published. To our knowledge, an intracranial oligodendroglioma presenting with symptoms of drop metastases in the cauda equina has never been reported. We report a case of 67-year-old woman who after 1 month of severe low back and legs pain developed symptoms of raised intracranial pressure. A spinal cord MRI showed multiple intradural nodular lesions at the level of the cauda equina, a MRI of the brain showed an intraventricular brain tumor. The histopathological diagnosis of both surgically treated lesions was anaplastic oligodendroglioma. The choices adopted in planning diagnostic and therapeutical procedures are discussed. The importance of the clinical and neuroradiological data in the diagnosis is stressed. Pathophysiology of the seeding of intracranial tumours via the cerebrospinal fluid is reviewed ²⁾.