Castleman's disease is an uncommon lymphoproliferative disorder that manifests itself as a local or generalized tumor-like condition affecting both lymph nodes and nonnodal tissues, usually in the chest or abdomen. Only two prior examples involving the central nervous system had been reported when this patient was encountered. Very recently, three additional cases have been reported by Severson et al. We report the sixth case of Castleman's disease affecting the central nervous system, which occurred in a 63-year-old woman in whom the diagnosis was made after craniotomy for a mass lesion involving the dura over the frontal regions. Neuroradiological, clinical, and immunopathological characteristics of the case are presented. The lesion was treated with cranial irradiation and the patient is alive and symptom free three years after initial treatment.