Intracranial gliomas in neurofibromatosis type 1

Optic pathway gliomas and brainstem gliomas are the predominant intracrania l neoplasms associated with neurofibromatosis type 1 (NF1). Before the past 15 years, studies of optic pathway gliomas in NF1 were hampered by the ina ccurate diagnosis of NF1, the unavailability of noninvasive neuroimaging te chniques, and the frequent rendering of what would now be considered unnece ssary, overly aggressive therapy. When studied systematically, these tumors behave in a much more benign fashion than their counterparts in children w ho do not have NF1. While they may cause symptoms in as many of 50% of case s, progression to the point where specific intervention is deemed necessary is unusual. Consequently, screening neuroimaging of asymptomatic patients is unwarranted. Because optic pathway tumors universally arise in children younger than 7 years of age, all such children should undergo yearly ophtha lmologic evaluations and annual assessments of growth to monitor for signs of precocious puberty. Am. J. Med. Genet. (Semin. Med. Genet.) 89:38-44, 19 99. (C) 1999 Wiley-Liss, Inc.