NF2 Alteration/22q Loss Is Associated with Recurrence in WHO Grade 1 Sphenoid Wing Meningiomas

Sphenoid wing meningiomas account for 11–20% of all intracranial meningiomas and have a higher recurrence rate than those at other sites. Recent molecular biological analyses of meningiomas have proposed new subgroups; however, the correlation between genetic background and recurrence in sphenoid wing meningiomas has not yet been fully elucidated. In this study, we evaluated the clinical characteristics, pathological diagnosis, and molecular background of 47 patients with sphenoid wing meningiomas. Variants of NF2, AKT1, KLF4, SMO, POLR2A, PIK3CA, TRAF7, and TERT were determined using Sanger sequencing, and 22q loss was detected using multiplex ligation-dependent probe amplification. Alterations were localized at NF2 in 11 cases, had other genotypes in 17 cases, and were not detected in 12 cases. Interestingly, WHO grade 1 meningiomas with NF2 alteration/22q loss (p = 0.008) and a MIB-1 labeling index > 4 (p = 0.03) were associated with a significantly shorter recurrence-free survival, and multivariate analysis revealed that NF2 alteration/22q loss was associated with recurrence (hazard ratio, 13.1). The duration of recurrence was significantly shorter for meningiomas with NF2 alteration/22q loss (p = 0.0007) even if gross-total resection was achieved. Together, these findings suggest that NF2 alteration/22q loss is associated with recurrence in WHO grade 1 sphenoid wing meningiomas.