Central neurocytoma represents a tumor consisting of diverse neuronal phenotypes

Central neurocytoma (CN) has long been regarded as a neuronal tumor based on the immunohistochemical expression of synaptophysin and the ultrastructural observation of neurosecretory granules, neurites, and synapses. Having diagnosed 11 CNs at our institution over the past thirty years, we set out to conduct an immunohistochemical study to assess the expression profile of neuronal markers across our cases. Markers of interest included synaptophysin, alpha-synuclein, chromogranin, neurofilament, and calretinin. Intriguingly, we observed a dichotomous expression profile between neurofilament and calretinin, suggesting the presence of histologic variants of CN based on the degree of neuronal maturation. We have further provided an overview of the clinico-pathologic heterogeneity within our series with respect to age of onset, overall outcome, and presence of anaplastic features. In highlighting the case of an infant with an incidental CN diagnosed at autopsy, we have discussed the role of a primitive neural cell of origin for driving tumor formation and accounting for our proposed differences in neuronal maturation within CN.