An extra-axial, dural-based, avidly enhancing mass with a CSF cleft and dural tail; the report adds venous sinus invasion, hyperostosis, brain oedema and the features that suggest a higher grade.
Orient first
- Extra-axial signs: CSF cleft, displaced cortex and vessels, broad dural base, buckled grey matter.
- Hyperostosis of adjacent bone and calcification are common in benign meningioma.
- Features raising concern for atypical or anaplastic grade: brain invasion, heterogeneous enhancement, necrosis, marked oedema, low ADC (not reliable alone).
Acquire the study
- Post-gadolinium 3D T1, T2, FLAIR, DWI, MR venography for parasagittal lesions.
The manoeuvre
- Post-contrast T1 in three planes: dural base, dural tail, size in mm.
- T2: CSF cleft and vascular flow voids at the tumour–brain interface; brain oedema on FLAIR.
- Venous sinus on MRV and post-contrast series: patent, compressed or invaded (Sindou grade — verify).
- DWI: very low ADC in a meningioma raises concern for higher grade.
What confirms it
- A dural-based extra-axial enhancing mass with a CSF cleft; histology grades it.
What licenses you to exclude it
- Intra-axial location (no CSF cleft, cortex expanded) excludes meningioma.
The classic misread
- A dural tail is not specific — metastases, lymphoma and granulomatous disease can show it.