Positron emission tomography in three children with pleomorphic xanthoastrocytoma.

The pleomorphic xanthoastrocytoma is generally considered a low-grade neoplasm with favorable prognosis. These tumors, however, can demonstrate primary anaplastic features, undergo malignant transformation, disseminate, or progress with poor outcome. Currently, there are no histologic or clinical features that reliably predict recurrent tumor or tumor progression.