Meningiomas are common in adults (~35% of brain tumors) but rare in children, where they exhibit unique clinical, pathological and molecular features compared to adult counterparts. Thus, data generated from adult cohorts may be imperfectly suited to guiding diagnostic, prognostic and treatment decisions for children. We studied 50 meningioma patients ≤18 years with available clinical and pathological data to address the need for data obtained in the pediatric setting. As previously described, we noted a slight bias toward male patients and a higher proportion of spinal tumors compared to adults. Thirty‐eight of 50 specimens were further analyzed by next generation sequencing. Loss‐of‐function mutations in NF2 and chromosome 22 losses were common, but pathogenic variants in other genes (SMARCB1, FUBP1, BRAF, TERT promoter, CHEK2, SMAD and GATA3) were identified in a minority of cases. Copy number variants outside of chromosomes 22 and 1 were infrequent. H3K27 hypomethylation, a useful biomarker in adult tumors, was not found in our cohort. In exploring the correlation between mitotic count and recurrence‐free survival, we found a threshold of six mitoses per 10 high powered fields as the optimal cutoff in predicting recurrence‐free survival. If independently validated in larger studies, adjusted grading thresholds could enhance the clinical management of pediatric meningiomas.

中文翻译：

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小儿脑膜瘤：具有潜在分级意义的临床病理学和分子研究。

脑膜瘤在成人中很常见（约占脑肿瘤的 35%），但在儿童中很少见，与成人相比，它们表现出独特的临床、病理和分子特征。因此，从成人队列生成的数据可能不完全适合指导儿童的诊断、预后和治疗决策。我们研究了 50 名 ≤ 18 岁的脑膜瘤患者，并提供了可用的临床和病理数据，以满足对在儿科环境中获得的数据的需求。如前所述，我们注意到与成人相比，男性患者略有偏向，脊柱肿瘤的比例更高。通过下一代测序进一步分析了 50 个样本中的 38 个。NF2功能丧失突变和 22 号染色体丢失很常见，但其他基因的致病变异（SMARCB1、FUBP1、BRAF、TERT启动子、CHEK2、SMAD和GATA3）在少数情况下被鉴定。染色体 22 和 1 之外的拷贝数变异并不常见。H3K27 低甲基化是成人肿瘤中有用的生物标志物，但在我们的队列中未发现。在探索有丝分裂计数与无复发生存率之间的相关性时，我们发现每 10 个高倍视野 6 个有丝分裂的阈值是预测无复发生存率的最佳临界值。如果在更大的研究中独立验证，调整后的分级阈值可以增强小儿脑膜瘤的临床管理。