A ganglioglioma (or gangliocytoma) is a rare, slow-growing primary central nervous system (CNS) tumor which most frequently occurs in the temporal lobes of children and young adults.

Poor prognostic factors for adults with gangliogliomas include older age at diagnosis, male sex, and malignant histologic features.

Fibrovascular stroma confined to the neuronal component, perivascular lymphocytic infiltrates, and small foci of calcification are common, as is immunopositivity for synaptophysin, neuron-specific enolase, and chromogranin A. Elevated Ki-67 and p53 labeling index is associated with more aggressive tumor behavior in both children and adults with gangliogliomas.

The rare occurrence of malignant transformation is confined to the glial cell population, and is characterized by increased cellularity and mitotic activity, endothelial proliferation, and necrosis.

Poorly defined margins may be more suggestive of astrocytoma, while a central location in the spinal cord, hemorrhage, and hemosiderin staining are often seen with ependymoma.