A 60-year-old woman presents with progressive headache and personality changes. MRI shows a well-circumscribed, homogeneously enhancing extra-axial mass attached to the dural surface with a dural tail sign. Histology shows whorled arrays of meningothelial cells with psammoma bodies. What is the WHO grade of this tumor in the absence of brain invasion or high mitotic activity?

• A CNS WHO grade 4
• B CNS WHO grade 2
• C CNS WHO grade 3
• D CNS WHO grade 1 ✓

Explanation

Meningioma with meningothelial histology, whorls, and psammoma bodies without brain invasion, high mitotic rate, or atypical features is CNS WHO grade 1. Grade 2 (atypical) requires either 4-19 mitoses per 10 high-power fields or brain invasion. Grade 3 (anaplastic/malignant) requires 20 or more mitoses per 10 high-power fields or frankly sarcomatous/carcinomatous histology. The dural tail sign is a classic imaging feature.

Reference: WHO Classification of Tumours of the Central Nervous System, 5th (2021) ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.