Is bone removal necessary during meningioma surgery?

Bone Removal in Meningioma Surgery

Yes, bone removal is necessary during meningioma surgery when hyperostosis or bone invasion is present, as resection of the dural origin/attachment and involved bone is recommended to reduce recurrence risk. 1

Surgical Approach to Bone Involvement

The evidence strongly supports aggressive bone resection in meningioma surgery, particularly when radiological hyperostosis is identified:

When to Remove Bone

Resection of the dural origin/attachment is recommended as there is a higher reported incidence of recurrence if dural attachment is left behind. 1 This principle extends to bone involvement:

• Hyperostosis is present in 75% of meningioma cases and represents actual tumor invasion in 20% of patients 2
• Among patients with radiological hyperostosis, tumor invasion of bone occurs in 23% (7 of 30 cases) 2
• Convexity meningiomas show the highest rate of bony invasion at 33.3% 2

Extent of Bone Resection

For WHO Grade I and II meningiomas: Remove the gross epicenter of hyperostotic bone plus a 2 cm margin around the visible nidus to ensure pathologically free margins 3

For WHO Grade III (anaplastic) meningiomas: More extensive bone removal is required, as tumor cells extend beyond the 2 cm margin in these aggressive tumors 3

Special Considerations for Spheno-Orbital Meningiomas

Direct removal of the affected greater sphenoid wing is beneficial in oncological control, as tumor invasion to the affected bone was observed in all cases of spheno-orbital meningiomas 4. The surgical technique should promote:

• Removal of temporal intradural tumor
• Decompression of lateral orbital wall
• Decompression of optic canal and superior orbital fissure

Critical Pitfalls

Do not replace the bone flap when hyperostosis is present. The recommendation is to remove the bone whenever possible to achieve total excision and use synthetic material to cover the defect 2. This is particularly important because:

• Invasion of bone is not considered a sign of malignancy 1, meaning even benign meningiomas can invade bone
• Bony hyperostosis represents actual tumor infiltration, not just reactive changes, in a significant proportion of cases
• Radiotherapy planning should include the dural tail and any abnormal bone on radiology 1

Practical Algorithm

1. Preoperative imaging: Identify hyperostosis on CT (appears as hyperdense bone) and T2 hyperintense signal changes on MRI
2. Intraoperative decision: Remove all visible abnormal bone including hyperintense diploe on MRI T2
3. Margin assessment: Extend bone removal 2 cm beyond visible hyperostotic nidus for Grade I/II tumors
4. Reconstruction: Use synthetic material rather than replacing potentially invaded bone flap
5. Pathological confirmation: Send bone specimens for histopathological examination to confirm invasion

Note: T2 hyperintense signal changes extending beyond visible hyperostotic areas don't necessarily represent tumor invasion 3, but the visible hyperostotic bone itself should still be completely removed with adequate margins.