Background: Primary meningeal melanocytic tumors are ultra-rare entities with distinct histological and molecular features compared with other melanocytic or pigmented lesions, such as brain and leptomeningeal metastases from metastatic melanoma. Methods: The European Network for Rare Cancers (EURACAN) Task Force on Ultra-Rare Brain Tumors (domain 10, subdomain 10) performed a literature review from January 1985 to December 2023 regarding the epidemiologic and clinical characteristics, histological and molecular features, radiological findings, and efficacy of local treatments (surgery and radiotherapy) and systemic treatments for these entities. Results: Molecular analysis can detect specific mutations, including GNAQ, GNA11, SF3B1, EIF1AX, BAP1, that are typically found in circumscribed primary meningeal melanocytic tumors and not in other melanocytic lesions, whereas NRAS and BRAF mutations are typical for diffuse primary meningeal melanocytic tumors. The neuroimaging of the whole neuroaxis suggests a melanocytic nature of a lesion, depicts its circumscribed or diffuse nature, but cannot predict the tumor’s aggressiveness. Gross-total resection is the first choice in the case of circumscribed meningeal melanocytoma and melanoma; conversely, meningeal biopsy may be reserved for patients with diffuse and multinodular leptomeningeal spread to achieve a definitive diagnosis. High-dose radiotherapy is rarely indicated in diffuse melanocytic tumors except as palliative treatment to alleviate symptoms. Last, a definitive advantage of a specific systemic treatment could not be concluded, as most of the data available derive from case reports or small cohorts. Conclusions: As primary meningeal melanocytic tumors are extremely rare, the correlations between the clinical characteristics, molecular profile, radiological findings at diagnosis and progression are weak, and poor evidence on the best therapeutic approach is available. There is a need to develop shared platforms and registries to capture more knowledge regarding these ultra-rare entities.
背景：原发性脑膜黑色素细胞肿瘤是极为罕见的疾病，其组织学和分子特征与其他黑色素细胞或色素性病变（如转移性黑色素瘤的脑及软脑膜转移）存在显著差异。方法：欧洲罕见癌症网络（EURACAN）超罕见脑肿瘤工作组（领域10，子领域10）对1985年1月至2023年12月期间关于此类肿瘤的流行病学与临床特征、组织学与分子特征、影像学表现，以及局部治疗（手术与放疗）和全身治疗疗效的文献进行了系统性回顾。结果：分子分析可检测到特定突变，包括GNAQ、GNA11、SF3B1、EIF1AX、BAP1，这些突变通常见于局限性原发性脑膜黑色素细胞肿瘤，而不见于其他黑色素细胞病变；而NRAS和BRAF突变则是弥漫性原发性脑膜黑色素细胞肿瘤的典型特征。全神经轴影像学检查可提示病变的黑色素细胞性质，显示其局限性或弥漫性特征，但无法预测肿瘤的侵袭性。对于局限性脑膜黑色素细胞瘤和黑色素瘤，全切手术是首选治疗；相反，对于弥漫性、多结节性软脑膜播散的患者，可考虑进行脑膜活检以明确诊断。高剂量放疗在弥漫性黑色素细胞肿瘤中很少适用，多仅作为缓解症状的姑息治疗。最后，由于现有数据大多来自病例报告或小规模队列研究，目前无法确定特定全身治疗的明确优势。结论：由于原发性脑膜黑色素细胞肿瘤极为罕见，其临床特征、分子谱、诊断与进展时的影像学表现之间的关联性较弱，且关于最佳治疗方案的证据不足。有必要建立共享平台和登记系统，以获取更多关于这些超罕见疾病的知识。
肿瘤(癌症)患者之家