atypical meningioma

Pathology

• tendency to recur;
• corresponds histologically to grade II

Microscopic pathology

• meningioma with increased mitotic activity (4 or more/10 HPF) or three or more of following features:
  • increased cellularity
  • small cells with high nuclear cytoplasmic ratios
  • prominent nucleoli
  • uninterrupted patternless or sheetlike growth
  • foci of spontateous or geographic necrosis

Genetics

see meningeal neoplasm

More general terms

• meningioma