Treatment of Medulloblastoma in adults

Medulloblastoma (M) is an aggressive posterior fossa tumour that probably originates from germinative neuroepithelial cells in the fourth ventricle (however, histogenesis is very controversial). Medulloblastoma accounts for 1% of all adult brain tumours and 25% of brain tumours in children. It is exceptional in patients aged over 16 years, while the median age of adult medulloblastoma is about 28 [1]. The most common revealing symptoms are: intra-cranial hypertension, cerebellar disorders and palsy of cranial nerves. In adults, the MRI findings show an homogeneous tumour predominantly located in the cerebellar hemisphere, poorly defined with weak contrast enhancement, with hypersignal flair and hypo-signal T1. Laterally located tumours are most common in adults compared to children (30% versus 7%). The WHO histological classification distinguishes 4 classical subtypes (classic M, extensive nodulary M, desmoplastic M and large cell M) and 2 rare subtypes (melanocytic M and medullomyoblastoma). The desmoplastic subtype is more frequent in adults than in children (40% versus 15%). Metastasis is more common in adults than in children: initial spinal or cerebral metastasis in about 30% of cases, cerebrospinal fluid involvement in about 30% of cases and metastasis outside the CNS (bone) in 5% of cases [1, 3, 7]. A specific TNM classification has been described by [3].