Outcomes for individuals with meningioma previously classified as World Health Organization grade I


  • Brain invasion was common in individuals with meningiomas World Health Organization (WHO) grade I when brain/meningioma interface was available for histology (16.5%). However, brain invasion did not impact progression-free survival (PFS).

Why this matters

  • The 2016 revision of the WHO classification introduced brain invasion as a single sufficient criterion for grading as meningioma grade II, which might result in more aggressive adjuvant treatment strategies in these individuals.

  • This study suggest that treatment decisions solely based on the presence of microscopic brain invasion should be critically discussed and investigated further in prospective controlled trials.