NCOG-25. SINGLE-INSTITUTION SERIES OF SPINAL EPENDYMOMA IN CHILDREN WITH NF2-RELATED SCHWANNOMATOSIS

Abstract NF2-related schwannomatosis (NrS) is a tumor predisposition syndrome that results in the development of multiple central nervous system tumors, including spinal ependymomas (SP-EPN). SP-EPN are intramedullary tumors that are slow growing but can displace critical nerve pathways in the spinal cord, resulting in motor and sensory deficits that contribute to patient morbidity. Although surgery is the mainstay of treatment, it can also result in high morbidity, resection of sporadic SP-EPN is often curative; however, SP-EPN in NrS patients will often regrow, possibly resulting in additional surgeries and a lifetime of deficits, especially impacting pediatric patients. Yet, natural history and clinical outcomes for pediatric NrS patients with SP-EPN have not been well described. We reviewed 27 pediatric NrS patient cases from 1993 to 2023 at our institution and identified 10 patients with a diagnosis of SP-EPN, with a range of 1-3 tumors present at patient diagnosis. Demographic, clinical, pathologic, and radiologic data were collected from electronic medical records. Median age of diagnosis of NrS was 12 years old (range: 5-17) and median time from NrS diagnosis to SP-EPN diagnosis was 31 days (range: -1-1636). 14 out of 16 (87.5%) initial tumors were in the cervical spine region, with C2 being the most frequently involved level. Two patients underwent resection of their tumors, with both experiencing progression of their disease and one developing paraplegia. The most common symptoms from SP-EPN were pain (30%), motor deficits (30%), and sensory deficits (30%). 40% of the patients had progressive disease at last follow up, with median time from diagnosis to progression of 3.33 years. Median time from SP-EPN to last follow-up was 4.08 years. This series showcases the burden of SP-EPN in pediatric NrS patients, emphasizing the need for further exploration into clinical outcomes and novel treatments for this debilitating condition.