Calvarial angiomatous meningioma developed in the diploe

Background: Angiomatous meningioma is a rare subtype of meningiomas. To the best of our knowledge, there have been no reports of intradiploic angiomatous meningioma. Case Description: A 53-year-old previously healthy woman was diagnosed with a calvarial lesion during a brain checkup. Cerebral magnetic resonance imaging showed an intradiploic tumor, 11 × 14 × 12 mm, in the right parietal bone. It was an enhancing, lobular tumor presenting as isointensity on T1- and hyperintensity on T2-weighted sequences, with an intense enhancement of the adjacent dura mater. Computed tomography revealed bone erosion at the tumor site, extending predominantly into the inner side, and sclerotic changes in the surrounding bone. Total resection was performed. Microscopically, the tumor tissue comprised cells with low-grade meningioma and intervening prominent vasculatures, consistent with angiomatous meningioma. Conclusion: Angiomatous meningioma should be considered as a differential diagnosis when an intradiploic tumor shows a lobular structure, intense enhancement of the adjacent dura mater, and sclerotic changes in the surrounding skull. These findings can support prompt tumor resection.