Meningeoma are benign tumors arising from the arachnoid in the brain and spinal cord. Lately there is a growing emphasis on individualized prognostication, incorporating DNA methylation profiles alongside WHO grading. Our study aimed at reporting the use and clinical significance of routine epigenetic testing of meningiomas.

We retrospectively analyzed meningioma patients operated between Januar 2021 and August 2023 with comprehensive demographic information. Histological examinations and genome wide DNA-methylation analyses were performed by an independent neuropathologist.

80 patients were included in our study. Median age was 64 years, with a female predominance of 17-to-63 patients. 74 patients (93%) had WHO grade 1 meningiomas, 5 (6%) WHO grade 2 meningioma, and 1(1%) WHO grade 3 meningioma. In epigenetic analyses, 48 (60%) of meningiomas were classified as benign,9 (11%) as intermediate,and 1(1%) as malignant, while 19 tumors (24%) remained unclassified and 3(4%) were not epigenetically tested. Among WHO grade 1, 45 patients (61%) presented as benign, 8 (11%) intermediate, 4 (24%) unclassified. The single case with malignant classifier had a WHO grade 3 meningioma. The initial histological report, categorizing WHO grades, was typically obtained soon postoperatively, with a median turnaround time of 5 days. The tumor board convened at a median interval of 8 days. Subsequently, the second histological report, focusing on epigenetic analysis, was acquired later (median 22d). We found significant association between meningioma classifier and progression (r -0.37, p=0.0046, Spearman test). Additionally, a positive correlation was observed between meningioma classifier score and tumor volume (r 0.53, p <0.0001, Spearman test).No correlations were found between the meningioma classifier and the presence of edema or calcification on brain imaging. Similarly, no correlation was observed between the classifier and clinical performance status (KPS) at three months post-op, suggesting that the classifier likely does not influence the clinical course.

There is a high concordance between WHO grade and methylation classifier score in real-life meningioma treatment.10% of the patients had a higher classifier score than WHO grade, but this did not translate into management changes. The classifier score usually is not known when postsurgical follow-up and treatment plans are discussed. Thus, the clinical relevance of routine methylation analysis is unclear.