Bale TA, Benhamida J, Roychoudury S, et al. - Experts define a morphologically distinct pattern of tumor infarction and associated sarcoma-like changes, mimicking focal anaplasia, in otherwise WHO grade I meningiomas. The presented nine cases that showed a discrete spindle-cell (pseudosarcomatous) component with brisk mitotic activity (12–14 mitoses/10 HPF), elevated Ki-67 (mean 75.5 ± 25.0%, quantified), absence of PR, SSTR2A, or EMA expression, and potential SMA expression (50%). The progression rate was high, in contrast, among a comparison (control) cohort of consecutive WHO grade II and III meningiomas (n = 16). The data indicated that pseudosarcomatous changes describe reactive changes to central meningioma infarction, rather than focal anaplasia, and additional support the application of DNA methylation-based analysis as a beneficial adjunct for prognosticating meningioma behavior.