Third Ventricle Anaplastic Oligodendroglioma: A Case Report

Background and Importance: Anaplastic Oligodendroglioma (ODG) constitutes 24% of all pediatric ODG. The mean age of presentation of ODG is 12±6 years. They are most common in frontal and temporal lobes; however, rare cases of intraventricular ODGs are reported. Most commonly they arise from the anterior part of lateral ventricles. Third ventricle ODG is extremely rare and only a few cases of lateral and third ventricle anaplastic ODG are reported. ODGs infiltrate locally to meninges and rarely have leptomeningeal spread. Thus, ODG forms a differential diagnosis of pediatric intraventricular tumor. Case Presentation: Here we present a case of a 15-month-old male child with raised intracranial pressure due to obstructive hydrocephalus. The patient was detected to be COVID-19 RT–PCR (Reverse Transcriptase Polymerase Chain Reaction) positive in the preoperative period and underwent emergency Right-sided Ventriculo Peritoneal (VP) shunt. His contrast MRI (Magnetic Resonance Imaging) Brain showed a 50×24×39 mm heterogeneously enhancing mass epicenter at third ventricle and extending to lateral and fourth ventricle with spinal drop metastasis. Preoperative differential diagnosis of Ependymoma was made and definitive surgery was done once the child recovered from COVID-19. However, his biopsy specimen pathology and Immunohistochemistry (IHC) were suggestive of anaplastic oligodendrogliomas and the child responded well to chemotherapy. Conclusion: Intraventricular ODG is an extremely rare pediatric tumor. Patients usually present with obstructive hydrocephalus. Contrast MRI findings are nonspecific and help in detecting leptomeningeal spread to the spine. IHC and chromosomal analysis are important diagnostic and treatment prognostication tools. These tumors have a high recurrence and poor prognosis despite gross total resection.