A 10 year old boy presents with midline swelling arising from cerebellum the diagnosis is –

Midline swelling arising from cerebellum in a child favour the diagnosis of medulloblastoma. Robbin's states "In children medulloblastomas are located in midline but in adults they are found in lateral locations". Note - Astrocytoma is also a posterior fossa tumor, but it does not commonly present as midline mass.