MR findings in childhood gangliogliomas.

Gangliogliomas are uncommon primary brain tumors composed of atypical glial and neuronal cells. These tumors usually occur in children and young adults. They are slow-growing tumors that present with seizures. We have reviewed four cases from our institution and have correlated the magnetic resonance (MR) findings with CT and histology. Two distinct patterns were observed with MR. In three of four patients, ranging in age from 7 to 14 years, MR showed a mass with decreased signal on T1-weighted images (WI) and increased signal on T2WI. The most common CT finding was a hypodense enhancing mass with focal calcifications. The histologic features of these tumors comprised microcysts and hypervascularity. In one of four patients, an infant. MR showed increased signal on T1WI and decreased signal on T2WI. Computed tomography showed a hyperdense nonenhancing mass. Histology demonstrated an increase of hypercellularity with both atypical glial and neuronal components.