Objective:Central neurocytomas are uncommon tumors ofthe central nervous system.In order to get better recognition ofcentral neurocytoma and diminish misdiagnosis

15 cases of central neurocytoma were analyzed by retrospective study.Methods:All cases of central neurocytoma were analyzed for their clinical symptoms

pathologic changes

immunohistochemical staining

prognosis and differential diagnosis.Clinical follow-up was available for 11 patients.Results:There were 8 males and 7 females whose ages ranged from 10 to 64 years(median 32.93 years).The most common presenting symptoms were those related to increased intracranial pressure(ICP)

including headache(100%)

papilledema(93%)and vomiting(80%).All tumors were located in the ventricular system.The tumors were composed of uniform cells with round nuclei and a fine chromatin pattern and small cells with perinuclear halo in some areas can be seen.In particular

a fine fibrillary matrix(neuropi)lin the anuclear areas can be seen.Nuclear atypia and vascular proliferation showed in two cases

respectively.Focal necrosis could be seen in one case.Immunohistochemical findings included expression of synaptophysin (15/15)

neuron specific enolase(12/15)and glial fibrillaryacidic protein(3/15).While MIB-1 proliferation indexranged from0.8% ～12.5%

and were more than 2%in 3 of 15 cases assessed.Follow-up information was available for eleven patients.Conclusion:Central neurocytomas have a favorable prognosis in general

but the clinical course of some cases could be aggressive.Increase of GFAP positivity

proliferation index and vascular proliferation might suggest a more malignant process.