Atypical ganglioneurocytoma: case report and review of literature

Abstract

Extra-ventricular neurocytoma (EVN) is a distinct neuro-pathological entity that has received increasing attention as the routine use of immunohistochemical staining has helped to distinguish it from oligodendroglioma; its more common morphologic mimic. Ganglionic differentiation in parts of the tumor is common, hence lending the name of Ganglioneurocytoma. Generally considered as low-grade tumors, recent literature highlights clinical examples with atypical pathologic features that elevate the grade of these tumors to World Health Organization (WHO) grade III and portend a worse prognosis. Biological progression to a higher tumor grade, serially over time in the same patient, has not been previously described. We report a case of low-grade ganglioneurocytoma (WHO grade II) that recurred with increased proliferation index and atypical features (WHO grade III). This case illustrates the challenges involved in precise grading of these tumors. Also exemplified is the unpredictable potential of seemingly low-grade lesions. Gross total resection and routine follow-up are essential for optimum treatment, as EVNs are associated with worse prognosis than their intra-ventricular counterparts.