Abstract
Meningioma is the most common primary intracranial tumor in adults, with up to 10% manifesting as multiple tumors. Data on the genomic and molecular changes in sporadic multiple meningiomas are scarce, leading to ongoing debates regarding their evolutionary processes. A comprehensive genetic analysis of a large number of lesions, including minute occult meningiomas (MOMs), is necessary to explore these two possible origins: clonal and independent. In the present study, we performed whole-exome sequencing and analyzed somatic single-nucleotide variants (SNVs), insertions/deletions (INDELs), and copy number alterations (CNAs) in a patient with sporadic multiple meningiomas. These meningiomas included two mass-forming lesions of different histological subtypes (transitional and chordoid) and three MOMs. Genetic analysis revealed CNAs on chromosomes 22q and Y as common abnormalities in the two largest tumors. Furthermore, we identified SNV/INDELs unique to each focus, with NF2 mutation prevalent in the transitional meningioma and CREBBP mutation in the chordoid meningioma. Loss of chromosome 22 was detected in all three MOMs, whereas an NF2 somatic mutation was found only in the largest MOM. Overall, we elucidated the clonal origin and histotype-specific evolution of multiple meningiomas in this case. CNAs may serve as the initial driving event in meningioma development.