Central neurocytoma: proliferative potential and biological behavior

Abstract

The authors analyzed 13 central neurocytomas diagnosed at Seoul National University Hospital between January 1982 and December 1993 to clarify the proliferative potential and biological behavior of these tumors. The tumor was confined to the lateral and third ventricles in 12 cases and in one case extended from the posterior thalamus to the body and trigone area of the lateral ventricle. In all 13 cases, typical clinical and radiological findings were observed, and histological diagnosis was performed via craniotomy. The diagnosis was made using light microscopic examination, immunohistochemical staining for neuronal markers, and electron microscopic findings of neuronal differentiation. One patient died due to tumor progression with recurrence 26 months after subtotal removal plus radiation therapy. Another patient had a recurrence 18 months after total tumor removal. The remaining 11 patients are free of recurrent tumor after a follow-up period that ranged from 14 to 109 months (median 50 months). To predict the proliferative potential, immunoreactivity to proliferating cell nuclear antigen (PCNA), silver colloid staining for nucleolar organizing regions (AgNORs), and DNA flow cytometry were performed in 10 of the 13 cases. The proportion of PCNA-positive cells was less than 1% in all cases and the AgNORs score ranged from 1.11 to 2.0 (mean 1.67). The DNA flow cytometry revealed diploidy in all cases and the calculated proliferation index ranged from 5.1% to 9.6% (mean 7.8%). The one case of tumor recurrence, in which the authors performed the study of proliferative potential, and another case that demonstrated mild nuclear pleomorphism also showed low percentages of PCNA-positive cells, low AgNORs scores, and diploidy in DNA flow cytometry. It is suggested that most central neurocytomas follow a benign clinical course with low proliferative potential assessed by PCNA, AgNORs, and DNA flow cytometry; however, recurrence is possible within a relatively short time period.

Central neurocytoma: A clinical, radiological and pathological study of nine cases

“…Limited data reported previously showed that central neurocytomas have low proliferative potential [3,43,44]. However, anaplasia has been demonstrated in recent literatures.…”

“…This report resulted in increased recognition of central neurocytomas and a number of case reports and series have been published since [1,2,3,36,39]. Despite their increased recognition, central neurocytomas remain rare neoplasms of the central nervous system.…”

“…Overall, they compromise only 0.25-0.5% of brain tumors [2]. The main features of central neurocytoma include: 1) a lateral ventricular location, 2) occurrence in young adults, 3) characteristic radiological findings, 4) resemblance to oligodendroglioma or ependymoma on light microscopy, 5) a neuronal origin seen on electron microscopic and immunohistochemical examination, and 6) a favorable prognosis with benign biological behavior [2,3]. The diagnosis and management of this tumor remains controversial.…”

Gamma Knife Radiosurgery for Central Neurocytomas

“…2,3,8,10,19) Standard initial treatment for central neurocytomas is a total resection whenever possible. 1,2,8,16,17,19,27) Histological and immunohistochemical examinations are necessary to establish the diagnosis differentially from oligodendroglioma or ependymoma. 3,8,9,13,15,19,22,29) The prognosis is usually favorable after gross total resection.…”

Neuronal and Mixed Neuronal-Glial Tumors of the Central Nervous System

“…However, Tumors with indices greater than 2%, as in one series in which they were found to be 3% , are referred to as "atypical neurocytomas" and associated with a significantly shorter recurrence-free interval (53,56,57). …”