NCMP-29. CEREBRAL EDEMA FROM RAPIDLY PROGRESSIVE METASTATIC CNS ATRT AND CHEMOTHERAPY INDUCED TUMOR LYSIS

Abstract

INTRODUCTION: Young pediatric patients with Central Nervous System (CNS) Atypical Teratoid Rhabdoid Tumor (ATRT) often present with metastasis and have extremely poor prognosis with the 2-year eventfree survival of 11% or less. We report a case of metastatic CNS ATRT with literature review. RESULTS: A 22-month-old girl presented with subacute onset ataxia, vomiting, weight loss, headaches, motor and speech regression followed by acute onset seizures. MRI brain revealed a heterogeneously enhancing solid-cystic pineal mass causing hydrocephalus. Tumor biopsy confirmed ATRT, WHO grade IV, SMARCB1/ INI1 loss CSF cytology revealed M3 disease. Germline rhabdoid predisposition syndrome was ruled out. The primary tumor was resected. Immediate postoperative MRI was concerning for further metastasis of the tumor. Chemotherapy based on Medical University of Vienna (MUV) protocol was begun but within 36 hours of doxorubicin, the patient succumbed to acute respiratory failure, hyponatremia, seizures and cardiac arrhythmia. CT head showed diffuse cerebral edema and early transtentorial herniation. A limited autopsy showed brain tissue studded with tumor cells. DISCUSSION: In our patient, the primary tumor was resected based on the reports of improved event-free survival in the setting of reduced tumor burden. MUV chemotherapy was started given its best-reported outcomes so far with the 5-year event-free survival of 89% in patients with M1-M3 CNS ATRT. Our patient may have suffered from doxorubicin-induced acute arrhythmia, rare but a known complication. In the light of rapidly metastasizing tumor, the possibility of doxorubicin-induced tumor lysis leading to acute cerebral edema cannot be excluded. Thus a combination of rapidly progressive metastatic tumor and rare chemotherapy complications may have led to the fatal outcome.