Evaluation of pleomorphic xanthoastrocytoma by use of positron emission tomography with [18-F]-fluorodeoxyglucose and [11C]-methionine tracers

We present a case of pleomorphic xanthoastrocytoma (PXA) in a patient with temporal lobe seizures. Imaging sequences included MR, and results of posit ron emission tomography (PET) with [18F]-fluorodeoxyglucose (FDG) and [11C] -methionine (Met) tracers revealed a hypermetabolic region equivalent or ne arly equivalent to normal cerebral cortex, suggesting that the tumor might have malignant potential, Histopathologic findings indicated low-grade glio ma. The mechanism for glucose hypermetabolic activity of PXA is not clear; however, the positive findings obtained from FDG-PET may not always indicat e the degree of malignancy associated with PXA.