ETMR-12. EMBRYONAL TUMOR WITH MULTILAYERED ROSETTES: A SINGLE CENTER EXPERIENCE

BACKGROUND: Embryonal tumor with multilayered rosettes (ETMR) is a rare, highly malignant tumor of the central nervous system and is usually diagnosed in children aged <2 years. Currently, because no defined treatment strategy has been reported, treatment regimens are often extrapolated from other embryonal tumors. Therefore, data collection of ETMR cases is important for further understanding EMTR. Here, we present our experience with four patients with ETMR. MATERIAL AND METHODS: Patients with a pathological diagnosis of ETMR from 1999 to 2016 at Saitama Children’s Medical Center were included. Their clinical data were retrospectively analyzed. RESULTS: This study included four cases of ETMR (one male and three females). The mean age at diagnosis was 29.5 (range, 15–37) months. Presenting symptoms included seizure, hemiparesis, vomiting, and headache. The mean maximal tumor diameter was 42.5 mm. The tumor locations included frontal lobe, temporal lobe, occipital lobe, cerebellum, and brainstem. Gross total resection was achieved in two cases. Fluorescence in situ hybridization analysis demonstrated amplification of 19q13.42 chromosome region in all cases, and diffuse positive expression was observed in the immunohistochemical staining for LIN28A. Systemic postoperative chemotherapy was administered to all patients. Three patients received intrathecal therapy and three were irradiated. The mean overall survival and progression-free survival were 45.3 and 42 months, respectively. Two patients who underwent gross total resection are alive without recurrence. CONCLUSION: Complete surgical resection may be an important prognostic factor in patients with ETMR. Further prospective studies are needed to confirm these results.