Buckland Ali, Green Celia, Kho Lay Kun, Prentice David
Neurology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, Western Australia, Australia.
BMJ Case Rep. 2021 May 24;14(5):e239496. doi: 10.1136/bcr-2020-239496.
Primary leptomeningeal melanomas are rare, comprising less than one percent of all brain tumours. They are aggressive and radioresistant tumours, with a poor prognosis. The mainstay of treatment is complete surgical resection and chemotherapy with limited success. Distinguishing a primary leptomeningeal melanoma from the more common metastatic disease can be difficult, and often requires the use of ancillary molecular testing. Primary central nervous system melanomas, including uveal melanomas, frequently exhibit mutations in GNAQ and GNA11, rare in the cutaneous and mucosal counterparts.A case of a primary leptomeningeal melanoma of the cerebellopontine angle is described. Molecular studies identified a GNA11 p.Q209L and a KIT p.M541L missense variant, with losses of chromosomes 1p and 3p demonstrated with cytogenetic studies. Complete surgical resection was not possible and leptomeningeal metastatic disease rapidly ensued despite immunotherapy. Further understanding of the molecular signature may translate to improved diagnosis, prognostication and development of targeted therapies.
原发性软脑膜黑色素瘤很罕见，占所有脑肿瘤的比例不到1%。它们是侵袭性且对放疗耐药的肿瘤，预后较差。治疗的主要方法是完全手术切除和化疗，但成功率有限。区分原发性软脑膜黑色素瘤与更常见的转移性疾病可能很困难，通常需要使用辅助分子检测。原发性中枢神经系统黑色素瘤，包括葡萄膜黑色素瘤，经常在GNAQ和GNA11中出现突变，这在皮肤和黏膜黑色素瘤中很少见。本文描述了一例小脑桥脑角原发性软脑膜黑色素瘤病例。分子研究鉴定出一个GNA11 p.Q209L和一个KIT p.M541L错义变异，细胞遗传学研究显示有1号染色体短臂和3号染色体短臂缺失。尽管进行了免疫治疗，但无法进行完全手术切除，软脑膜转移性疾病迅速出现。对分子特征的进一步了解可能有助于改善诊断、预后评估和靶向治疗的开发。
