Tumour cells have regular round and oval vesicualr nuclei, many with discernible nucleoli and delicate processes. Aggregates of nuclei are separated by fibrillary eosinophilic neuropil-like material. No mitotic figures are identified and there is no vascular endothelial cell proliferation or necrosis.
Tumour cells show strong peri-nuclear granular immunostaining for synaptophysin. No staining for epithelial membrane antigen (EMA) or GFAP is seen in tumour cells and there is no nuclear staining for Ki-67/MIB-1. The features are of central neurocytoma.
"Left lateral ventricle tumour": Central neurocytoma.