The pleomorphic xanthoastrocytoma and its differential diagnosis: a study of five cases.

Five brain tumors with the histopathologic features of pleomorphic xanthoastrocytomas (PXAs) are presented. Computed tomography scans showed a remarkable homology. Two cases had atypical localizations for a PXA, while one 46-year-old patient did not conform to the normal age distribution of this tumor. Nevertheless, in these cases, the histopathology was always characteristic for PXA, a remarkable pleomorphism, in addition to simultaneous expression of glial fibrillary acidic protein and histiocytic markers in the various tumor cells. In one of the presented tumors, however, clusters of neoplastic neuronal cells were also found. In this particular case, differential diagnostic criteria to distinguish between a PXA and a desmoplastic infantile ganglioglioma are lacking.