COMPOSITE PLEOMORPHIC XANTHOASTROCYTOMA AND GANGLIOGLIOMA - REPORT OF4 CASES AND REVIEW OF THE LITERATURE

Composite pleomorphic xanthoastrocytoma (PXA)-ganglioglioma (GG) is a rare recently described entity. Only three examples have been document ed, one of which showed evidence of malignant transformation. We repor t an additional four cases and update the literature. With the excepti on of an 82-year-old man, all patients have been under 30 years of age . The temporal lobe was involved in three cases and cerebellum in anot her three. Radiologic features were those common to PXA and GG. Histol ogically, all were ''collision tumors'' composed of abutting, although spatially distinct, PXA and GG components. In two cases, the second e lement was only recognized at reexcision or recurrence. Histologic ana plasia, always in the PXA component, was evident as brisk mitotic acti vity and/or necrosis in five cases. Of the seven patients, one died of disease 17 years after the onset of seizures and after multiple recur rences, the last of which largely resembled glioblastoma. We conclude that the composite PXA-GG is a rare neoplasm that shares many features of its individual components. In addition to its temporal lobe predil ection, the cerebellum is frequently affected. As when it occurs in is olation, the PXA component of composite PXA-GG possesses the potential for malignant transformation.