A clinicopathologic and immunomorphologic study of 13 cases of ganglioglioma

The authors present the clinical, histopathologic, and immunomorphologic data of 13 intracranial gangliogliomas. Preoperative computed tomography scans showed a commonly cystic tumor of variable density. Six tumors were completely excised and seven were subtotally resected. After a mean follow-up of 4.5 +/- 2.6 years, 11 patients are asymptomatic or only slightly incapacitated. All tumors were examined with a panel of neuronal and neuroendocrine markers. Immunoreactivity (IR) to anti-neurofilament polypeptide (clone 2F11) was observed in neuronal processes in ten cases and in neuronal perikarya in five. With anti-synaptophysin (clone SY38), IR was present along the lining of ganglion cell perikarya and processes in 11 tumors whereas staining of the perinuclear cytoplasm was prominent in two. IR to anti-chromogranin A (clone LK2H10) was observed within the neuronal perikarya in eight cases. Only one ganglioglioma of the brain stem showed IR for tyrosine-hydroxylase (clone 2/40/15) and dopamine-beta-hydroxylase in some neoplastic ganglion cells. In this study, synaptophysin was the most reliable neuronal marker. For immunocytochemical identification of neoplastic neurons in ganglioglioma as well as other tumors with neuronal differentiation the authors propose a panel of well-characterized monoclonal antibodies against neurofilament polypeptides, synaptophysin, and chromogranin A to support the histomorphologic diagnoses.