RADT-33. ANALYSIS OF PATIENTS DIAGNOSED WITH ATYPICAL TERATOID RHABDOID TUMOR OF BRAIN AT TERTIARY CARE CENTER

Abstract

Abstract Atypical Teratoid Rhabdoid Tumor (ATRT) of brain is highly malignant neoplasm with incidence of 1-2% among all pediatric CNS tumors characterized by mutations and subsequent inactivation of SMARCB1 (INI1, hSNF5) gene with dismal prognosis of about 6-18 months. On retrospective analysis of patients between 2010-2021 from Medical Record Department, only five cases of ATRT brain were retrieved. All patients were of pediatric age group (6 yr/F, 2yr/M, 6yr/F, 4yr/F, and 1yr/M – Median 4 yrs). On radiological findings, in four patients lesion was primarily in brain and in one patient with diffuse leptomeningeal enhancement. Three patients underwent craniotomy and gross total excision, and, in 2 patients only biopsy was done. In molecular analysis immunohistochemistry (IHC) markers were as follows. In all patients Vimentin and Synaptophysin were positive. EMA was positive in 3 patients, GPAP was positive in 3 patients, CD99 was positive in 2 patients, AE1 was positive in 2 patients. A specific marker for ATRT (INI1 loss) was seen in 3 patients. In other patients INI1 assessment could not be done. In two patients CSF cytology was negative, and, in all patients bone marrow examination was normal. One patient (4yr/F) received local radiotherapy with concurrent Vincristine based chemotherapy and lost to follow up (after 1 year of treatment). One patient (6yr/F) received vincristine based chemotherapy and local palliative radiotherapy and expired (after 1 month of treatment). One patient (6yr/F) received St Jude HR/IRS III protocol chemotherapy and craniospinal irradiation (CSI) and is still on follow up (total follow up period – 9 years). Two patients did not take any kind of treatment in whom one patient expired, another lost to follow up. Looking at rarity of tumors and with the review of literature, multiagent chemotherapy and Craniospinal irradiation seems to be promising approach for treatment of ATRT brain.