The patient went on to have a resection.
Sections show fibrous dura and bony tissue fragments infiltrated by a moderately hypercellular meningioma with a well-developed syncytial architecture. Tumor cells demonstrate uniform nuclear features. No mitoses or areas of necrosis are identified. No brain tissue is present.
Decalcified sections confirm tumor bone invasion.
FINAL DIAGNOSIS: Intraosseous meningioma (WHO Grade I).