[Histogenesis of central neurocytoma: an immunohistochemical and electronmicroscopic study of four cases].

Four intraventricular central neurocytomas were studied histopathologically and intriguing findings were obtained with regard to the histogenesis of this tumor. The cases included 3 males and 1 female aged 17-25. The tumors had developed in the regions from the lateral to the third ventricles and were surgically removed in all the cases. A honeycomb appearance was recognized on H&E staining, and the calcification and latticed vascular findings closely mimicked the appearance of oligodendroglioma. A characteristic wide eosinophilic fibrous stroma was observed frequently. Immunohistochemically, all four cases were NSE-positive and strongly synaptophysin-positive, and by electronmicroscopy, neurosecretory granules and microtubules were observed in all cases and typical synapse structures in 2 cases. GFAP immunoreactivity and glial differentiation, including ependymal cells were exhibited electronmicroscopically, such as glial fibrils, basal bodies, centrioles and 9 + 1 patterned cilia-like structures in 2 cases. These findings suggest that central neurocytoma is an embryonal tumor in the wide sense, originating from the germinal matrix cell of the lateral ventricles and possessing multipotency, with potent differentiation from mature neurons.