Molecular evolution of metastatic meningioma: A case report.

Distant metastases in meningioma are rare, and the molecular drivers of meningioma spread are not well understood. We describe the case of a 63-year-old woman who was diagnosed with an intracranial meningioma in 2020 which was graded as an atypical meningioma with brain invasion. Local recurrence occurred 1 year later, and in 2023 bone metastases were resected from the thoracic wall and humerus. Molecular analyses from all tumor sites by next-generation sequencing and genome-wide methylation profiling revealed several molecular alterations (loss of 1chromosome 1p, 3p, 4q, 8p, 9p, 10p, 14q, 18q, 22q) already present in the first tumor which remained surprisingly stable during progression and metastasis. However, distant metastasis was exclusively associated with gain of chromosome 1q and 17q. All samples harbored a homozygous CDKN2A deletion. This case expands the knowledge about molecular alterations associated with bone metastases of aggressive meningiomas.