LATE SEQUELAE OF TREATED PLEOMORPHIC XANTHOASTROCYTOMA - MALIGNANT BRAIN-STEM ASTROCYTOMA OCCURRING 15 YEARS AFTER RADIATION-THERAPY

The pleomorphic xanthoastrocytoma (PXA) is a unique astrocytic neoplas m with an unexpectedly favorable prognosis despite striking pleomorphi sm of the cellular constituents. Although a majority of patients exper ience extended survival, these tumors may recur and some cases progres s to high-grade astrocytoma. Recurrence inevitably involves the anatom ic vicinity of the primary tumor. In this report, we describe a malign ant brain stem astrocytoma that occurred 15 years after surgery and ra diation treatment of a 16-year-old patient who had a temporal lobe PXA . To our knowledge, this is the first reported case of a malignant ast rocytoma arising outside the primary anatomic site of a previously tre ated PXA and likely represents a radiation-induced secondary neoplasm.