Extraventricular neurocytomas.

Extraventricular neurocytomas (EVNs) are rare neoplasms with many similar morphologic features compared with central neurocytomas. EVNs have been reported in a variety of locations and mainly occur within the cerebral hemispheres. These lesions display wide variability in morphologic features, cellularity, and proliferation rates. In addition, given their aggressive biological nature and tendencies to affect eloquent areas, EVNs are associated with a poorer prognosis. The epidemiology of these rare tumors is not definitively known, and effective treatment strategies have not been developed. This article reviews these tumors, including their epidemiology, clinical presentation, locations, radiological findings, treatment options, and prognosis.