**14. Medulloblastoma in adults**

Medulloblastoma is much less common in adults, accounting for less than 1% - 3% of primary CNS tumors [24, 113, 114]. The annual incidence of medulloblastoma is 1–1.5 cases per million in the general adult population and 80% occur before the end of the fourth decade [24, 113–115]. Treatment protocols are limited for adults and they are treated by heterogeneous ways using various chemo-radiotherapy regimens with surgery with post-operative CSI being the mainstay of treatment [115]. As late relapse is common among adult medulloblastoma patients, long-term follow-up is warranted. Spinal seeding at presentation is a poor prognostic factor for recurrence [114, 115]. Adult medulloblastomas are clinically similar to that in the pediatric population, but lateral location and desmoplastic type is more frequent in adults as opposed to the pediatric age group. Adult medulloblastomas are thus, more amenable to complete resection and better outcome is expected because of their locations and histopathological variants respectively [24, 113–116]. Relapse following complete treatment is relatively late in adults as compared to children and they have a relatively prolonged time from relapse to death [116]. As most treatment recommendations for adults are extrapolated from the experience in pediatric patients, a protocol from the time of diagnosis includes: increasing the intensity to identify metastasis; increasing the radiotherapy dose to the primary site; adding chemotherapy following radiotherapy in medically fit patients; and following-up the patients with PET or bone scan every 6 months for at least 3 years [117, 118].
