INNV-24. CONGENITAL EMBRYONAL TUMOR WITH MULTILAYERED ROSETTES AND TREATMENT IN A NEWBORN

Abstract BACKGROUND Embryonal Tumor with Multilayered Rosettes (ETMR) is a rare but deadly pediatric brain tumor with no standard of care treatment. We present a unique case of congenital ETMR and treatment strategy using intrathecal topotecan and no radiation therapy. Case report: A term baby was admitted to NICU at 12 hours of life with respiratory arrest requiring intubation. CT of the brain revealed a 4.2x3.9x3.5cm left posterior fossa hyperdense hemorrhagic mass with moderate hydrocephalus. She underwent posterior fossa craniotomy for biopsy and evacuation at two days of life. Pathology was consistent with an ETMR. MRI brain after first resection was not concerning. She underwent re-resection at 3 months of age due to re-growth (2x3x3cm). She was then treated as per Head Start 4 chemotherapy regimen with vincristine, cisplatin, etoposide, cyclophosphamide, and methotrexate, followed by consolidation with three tandem auto-hemopoietic stem cell transplants (HSCT) with carboplatin and thiotepa conditioning. Maintenance treatment consisted of intrathecal topotecan every four weeks (0.2mg per dose <1 year old, 0.25mg per dose when ≥1 year old) for 12 doses. She also received oral vorinostat (100mg PO QD) and isotretinoin (80mg/m2 divided BID) during maintenance for 1 year. No radiation was given. The treatment course was complicated by mucositis, febrile neutropenia, pseudomonas sepsis and an episode of respiratory arrest secondary to choking from epistaxis. The patient is currently doing well and continues to remain in remission for over seven months after end of treatment. CONCLUSION We present a case of congenital ETMR with a unique treatment option and strategy using Head Start 4 therapy with three tandem auto-HSCT as consolidation, followed by 12 months of maintenance therapy with intrathecal topotecan, oral vorinostat, and isotretinoin, without any radiation, leading to sustained remission.