A 40-year-old woman presents with chronic headaches and visual field examination reveals bitemporal hemianopia. MRI shows a well-circumscribed, enhancing sellar/suprasellar mass. Histology shows a monomorphic tumor with a whorled pattern, psammoma bodies, and cells with indistinct borders (syncytial appearance). Which feature is associated with atypical (WHO grade 2) meningioma?
- A Psammoma bodies
- B Whorl formation
- C More than 4 mitoses per 10 high-power fields ✓
- D Syncytial cells
Correct answer: C. More than 4 mitoses per 10 high-power fields
Explanation
This describes meningioma, the most common primary CNS tumor in adults. Atypical meningioma (WHO grade 2) is defined by 4 to 19 mitoses per 10 high-power fields, or brain invasion, or three of five specific features (increased cellularity, small cell change, prominent nucleoli, sheet-like growth, necrosis). Anaplastic (grade 3) requires 20 or more mitoses per 10 HPF. Psammoma bodies, whorls, and syncytial cells are features of benign (grade 1) meningiomas.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.