Primary Intraosseous Meningioma of the Sphenoid-Temporal bone with Single-Stage, 3D-Planned Cranioplasty: Case Report

Background: Primary intraosseous meningiomas are rare extradural tumors, representing less than 2% of all meningiomas. They are often slow-growing and may present with nonspecific radiological features, complicating diagnosis. Case Report: We report the case of a 48-year-old female with progressive left frontotemporal bulging over 12 months, without neurological deficits. Imaging revealed an osteoblastic lesion in the left sphenoid and temporal bones, causing mild compression of adjacent structures. The patient underwent craniectomy with complete tumor resection and immediate cranioplasty using a pre-planned customized prosthesis. Histopathology and immunohistochemistry confirmed a meningothelial meningioma, with tumor cells confined to intertrabecular bone spaces and free surgical margins, consistent with a primary intraosseous origin. Postoperative follow-up demonstrated excellent cosmetic results and no recurrence. Lessons: Primary intraosseous meningiomas pose diagnostic and therapeutic challenges due to their rarity and nonspecific imaging features. Histopathology remains essential for definitive diagnosis. Preoperative 3D prototyping and customized prosthesis planning can optimize surgical reconstruction, reduce deformities, and improve cosmetic and functional outcomes. This case highlights the importance of integrating clinicoradiological evaluation, histopathology, and modern reconstructive techniques to achieve complete resection and minimize recurrence.