Coexistence of a ganglioglioma and Rasmussen's encephalitis.

A small number of recent reports have documented coexisting cerebral pathologic entities in patients with Rasmussen's encephalitis. We report the case of a 4-year-old boy who presented with refractory seizures and was found to have both a ganglioglioma and Rasmussen's encephalitis of the same hemisphere. The patient ultimately underwent a functional hemispherectomy with excellent seizure control. We also review the clinical and pathologic hallmarks of both gangliogliomas and Rasmussen's encephalitis. We hope that the addition of this patient to the small but growing literature on dual pathology in Rasmussen's encephalitis may help shed some light on the etiology of this mysterious disease.