由于周围有几个精细结构存在，第四脑室的手术具有挑战性。传统方法难以对这些区域进行轻松的可视化，特别是在顶部的区域。得益于神经外科内窥镜技术的最新发展，可以通过生理通路进入第四脑室，避免对神经和血管结构造成不必要的应力或损伤。我们提出一例患有舌叶-上髓帆病变并曾经进行肺和胰腺腺癌手术切除的患者病例。通过麦氏孔进行内窥镜生物检查。对这种内窥镜方法的少数报道也进行了批判性评论。通过灵活内窥镜的枕后、经麦氏孔逆行内窥镜探测，可以清晰可见上髓帆，并且可以使用微创技术对病变进行诊断性活检。使用灵活内窥镜的逆行麦氏孔导航是一种安全且优雅的技术，适用于第四脑室中任何位置的病变，特别是其前端部分。版权所有© 2023 Elsevier Ltd.。保留所有权利。

Surgery of the fourth ventricle is challenging due to the presence of several surrounding delicate structures. Traditional approaches do not offer an easy visualization of these areas, especially those on the roof. Thanks to the most recent developments in neurosurgical endoscopy, it is possible to access the fourth ventricle via physiological pathways, avoiding unnecessary stress or damage to the nervous and vascular structures.We present the case of a patient with a lesion at the lingula-superior medullary velum, and an history of surgically resected lung and pancreatic adenocarcinomas. An endoscopic biopsy of the lesion through the foramen of Magendie was performed. The few reports on this endoscopic approach were also critically reviewed.The retrograde endoscopic exploration through a suboccipital, trans-Magendie foramen approach using a flexible endoscope allowed the clear visualization of the superior medullary velum and the possibility to obtain diagnostic biopsies of the lesion with a minimally invasive technique.The trans-Magendie navigation with a flexible endoscope is a safe and elegant technique to approach lesions located in any point of the fourth ventricle, particularly in its rostral portion.Copyright © 2023 Elsevier Ltd. All rights reserved.