Meningioangiomatosis occurs sporadically and in patients with neurofibromatosis. The literature, however, is unclear concerning the type of neurofibromatosis associated with meningioangiomatosis. Because determining which form of neurofibromatosis predisposes to meningioangiomatosis would clarify the genetic alterations of this lesion, we reviewed all reported cases of meningioangiomatosis associated with neurofibromatosis in light of current diagnostic criteria for neurofibromatosis 1 (NF1) and neurofibromatosis 2 (NF2). All well-documented cases of meningioangiomatosis occurred in the setting of NF2, implying that germline alterations of the NF2 gene predispose to meningioangiomatosis. To determine whether sporadic (non-NF) cases of meningioangiomatosis arise from somatic alterations of the same gene, we screened the NF2 gene for mutations in 12 sporadic cases of meningioangiomatosis and in constitutional DNA from 6 of these 12 patients. No mutations were found in either the lesional or constitutional DNA, which suggests that sporadic meningioangiomatosis is not a forme fruste of NF2 and that somatic alterations of the NF2 gene do not play a major role in sporadic meningioangiomatosis. For some tumor suppressor genes, germline mutations may predispose to specific tumors, while similar sporadic lesions only rarely suffer somatic mutations in these genes. The present findings suggest a similar dichotomy for the NF2 gene in meningioangiomatosis.