Pediatric Embryonal Tumors in True Rosettes (Etmrs) Presenting as a Low Grade Glioma– An Unusual Case Report

Pediatric Embryonal Tumors in Multilayered Rosettes (ETMR) are rare aggressive tumors with poor survival statistics, defined by the 2016 WHO classification of brain tumors. The tumors have a characteristic radiological appearance on MR imaging of the brain, which is easily decipherable. This combined with a clinical picture of raised intracranial pressure symptoms, seizures and rapidly progressive new onset neurological deficits make the diagnosis fairly obvious. The final confirmation of the diagnosis is done by immunehistochemical analysis of the C19Myc gene alteration. Rarely certain radiological presentations are uncharacteristic and resemble other more benign pathologies with overlapping clinical presentations. This can be misleading, as ETMRs require aggressive surgery followed by adjuvant chemotherapy and radiation to ensure best possible survival. We present such a case report of what appeared to be a low-grade glioma in the frontal lobe. This tumor presented with 1 episode of generalized tonic clonic seizures not unusual as a presenting complaint in low grade gliomas per se. Surgical debulking under Ultrasonic guidance was done and the specimen sent to histopathological analysis. The histopathological analysis showed a surprise ETMR diagnosis which was sent for confirmation to 2 other centers. This case report highlights the need to keep ETMRs as a rare differential diagnosis for even low-grade gliomas of the brain, thereby allowing accurate prognostication only after histopathological and immunohistochemical assessment. We present a brief literature review on unusual presentations of ETMRs reported in literature to further illustrate the chimeric nature of this rare disease.