Extraventricular neurocytoma of the vermis in a child.

Neurocytomas are rare neoplasms, composed of uniform round cells with neuronal differentiation. We report a rare extraventricular neurocytoma (EVN) in a 5-year-old boy who presented with headache and vomiting. His MRI brain showed a vermian mass. The histopathological examination and immunohistochemistry revealed it to be an EVN. We report this patient for the rarity of the condition and the EVN mimicking a medulloblastoma on imaging. This tumor needs to be differentiated from a medulloblastoma as the former has a better prognosis.