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A RECURRENT CEREBELLAR LESION IN A YOUNG BOY

Central neurocytomas typically grow from the foramen of Monro or the septum pellucidum, and represent less than 1% of all central nervous system tumors. They usually respond well with complete resection and affect young adults. Neurocytomas involving the cerebellum are rarer and they usually contain lipomatous areas (cerebellar liponeurocytomas). To our knowledge, there are only two reported cerebellar neurocytomas without lipomatous areas. Herein we report the case of a boy with a recurrent non-lipomatous cerebellar neurocytoma. The original tumor was composed of small neuronal cells often surrounded by clear halos. There is an eosinophilic fibrillar background. The lesion stains positively for synaptophysin and negatively for glial fibrillary acidic protein (GFAP). The tumor has recurred twice over 4 years with similar histology and immunophenotype. It should be emphasized that neurocytomas should be in the differential for lesions in the posterior fossa. Given the above morphology, neurocytomas can be misdiagnosed as clear cell ependymomas, lymphomas, oligodendrogliomas or neuroblastomas. Correspondence 627 Brain Pathology 18 (2008) 623–627 © 2008 The Authors; Journal Compilation © 2008 International Society of Neuropathology