MENINGIOANGIOMATOSIS IS ASSOCIATED WITH NEUROFIBROMATOSIS-2 BUT NOT WITH SOMATIC ALTERATIONS OF THE NF2 GENE

Meningioangiomatosis occurs sporadically and in patients with neurofib romatosis. The literature, however, is unclear concerning the type of neurofibromatosis associated with meningioangiomatosis. Because determ ining which form of neurofibromatosis predisposes to meningioangiomato sis would clarify the genetic alterations of this lesion, we reviewed all reported cases of meningioangiomatosis associated with neurofibrom atosis in light of current diagnostic criteria for neurofibromatosis 1 (NF1) and neurofibromatosis 2 (NF2). All well-documented cases of men ingioangiomatosis occurred in the setting of NF2, implying that germli ne alterations of the NF2 gene predispose to meningioangiomatosis. To determine whether sporadic (non-NF) cases of meningioangiomatosis aris e from somatic alterations of the same gene, we screened the NF2 gene for mutations in 12 sporadic cases of meningioangiomatosis and in cons titutional DNA from 6 of these 12 patients. No mutations were found in either the lesional or constitutional DNA, which suggests that sporad ic meningioangiomatosis is not a forme fruste of NF2 and that somatic alterations of the NF2 gene do not play a major role in sporadic menin gioangiomatosis. For some tumor suppressor genes, germline mutations m ay predispose to specific tumors, while similar sporadic lesions only rarely suffer somatic mutations in these genes. The present findings s uggest a similar dichotomy for the NF2 gene in meningioangiomatosis.