Pleomorphic Xanthoastrocytoma of the Pineal Region in a Pediatric Patient With Neurofibromatosis Type 1.

Pleomorphic xanthoastrocytoma (PXA) is a rare and often focal glioma that most commonly affects children and young adults. Lesions are preferentially supratentorial and superficial, although infratentorial masses have been described, along with occasional involvement of the leptomeninges. The World Health Organization (WHO) categorizes these tumors as grade II, with surgical resection carrying a favorable prognosis. However, these tumors may undergo malignant degeneration and must be identified for appropriate treatment and prognosis. PXA has been associated with neurofibromatosis type 1 (NF1), although it is not the classic phenotype of NF1. We present a novel report of PXA, atypically located in the pineal region of a patient with a history of NF1. A 17-year-old male with a history of NF1 presented with 1 month of bifrontal headaches. Magnetic resonance imaging was significant for a heterogeneous tectal mass, suspicious for a glioma extending to the fourth ventricle and causing displacement of the cerebral aqueduct without obstructive hydrocephalus. Following an infratentorial-supracerebellar approach for tumor resection, histopathology confirmed a low-grade variable neoplasm consistent with PXA. Postoperative imaging confirmed gross total resection with no evidence of recurrence at 9 months postoperatively. To our knowledge, this case is the fifth report of pineal PXA and the first associated with NF1. Because PXA presents similarly to other NF1-related intracranial tumors, careful diagnosis via immunohistochemistry is imperative. Gross tumor resection is usually curative; however, PXA has the propensity to undergo malignant degeneration and may require adjuvant treatment.