Central neurocytoma: proliferative assessment by nucleolar organizer region staining.

Proliferative potential of four cases of central neurocytoma were assessed by a silver colloid staining technique for argyrophilic protein associated with nucleolar organizer regions (AgNORs). All but one tumor had an Ag-NOR score of less than 2 and were regarded as a benign entity. However, one tumor tissue from a patient suffering from a recurrent central neurocytoma after 13 years from the first operation possessed a 2.06 AgNOR score, which is not significantly different from others. It is considered that central neurocytoma is an essentially benign neoplasm, even though the tumor is recurrent. The present study revealed the usefulness of AgNOR staining for a retrospective assessment of the proliferative potential of central neurocytomas.