Meningiomas are the most common primary intracranial tumors, but meningioma metastases are rare. Accordingly, the clinical workup, diagnostic testing, and molecular classification of metastatic meningioma is incompletely understood. Here, we present a case report of multiply recurrent meningioma complicated by liver metastasis. We discuss the patient presentation, imaging findings, and conventional histopathologic characterization of both the intracranial lesion and the metastatic focus. Further, we perform multiplatform molecular profiling, comprised of DNA methylation arrays and RNA-sequencing, of six stereotactically-guided samples from the intracranial meningioma and a single ultrasound-guided liver metastasis biopsy. Our results show that DNA methylation clusters distinguish the liver metastasis from the intracranial meningioma samples, and identify a small focus of hepatocyte contamination with the liver biopsy. Nonetheless, DNA methylation-based classification accurately identifies the liver metastasis as a meningioma with high confidence. We also find that clustering of RNA-sequencing results distinguishes the liver metastasis from the intracranial meningiomas samples, but that differential gene expression classification is confounded by hepatocyte-specific gene expression programs in the liver metastasis. In sum, this case report sheds light on the comparative biology of intracranial and metastatic meningioma. Furthermore, our results support methylation-based classification as a robust method of diagnosing metastatic lesions, underscore the broad utility of DNA methylation array profiling in diagnostic pathology, and caution against the routine use of bulk RNA-sequencing for identifying tumor signatures in heterogeneous metastatic lesions.

中文翻译：

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在转移性脑膜瘤的情况下，DNA甲基化分析显示出优于RNA测序的诊断分类。

脑膜瘤是最常见的原发性颅内肿瘤，但脑膜瘤转移很少。因此，对转移性脑膜瘤的临床检查，诊断测试和分子分类还不完全了解。在这里，我们提出一例多发性复发性脑膜瘤并发肝转移的病例报告。我们讨论了颅内病变和转移灶的患者表现，影像学表现和常规组织病理学特征。此外，我们对来自颅内脑膜瘤的六个立体定位样本和一次超声导向的肝转移活检进行多平台分子分析，包括DNA甲基化阵列和RNA测序。我们的研究结果表明，DNA甲基化簇可将肝转移与颅内脑膜瘤样本区分开，并通过肝活检确定肝细胞污染的一小部分。但是，基于DNA甲基化的分类可以高度准确地准确地将肝转移确定为脑膜瘤。我们还发现，RNA测序结果的聚类区分了颅内脑膜瘤样本的肝转移，但差异基因表达分类被肝转移中的肝细胞特异性基因表达程序所混淆。总之，本病例报告阐明了颅内和转移性脑膜瘤的比较生物学。此外，我们的研究结果支持基于甲基化的分类作为诊断转移性病变的可靠方法，强调了DNA甲基化阵列分析在诊断病理学中的广泛应用，