患者男,55岁,主诉右侧肢体沉重,乏力1年半。伸舌微向左偏斜,左侧肢体肌力Ⅴ级,右侧肢体肌力Ⅳ级。CT:左侧脑沟裂增多变宽,内可见不规则囊状、串珠状水样密度影,囊壁菲薄,主要以左侧外侧裂为主,部分延伸到鞍上池,增强扫描病变未见强化,周围见正常强化血管(图1,2)。手术所见:切开 Male patient, 55 years old, complained of severe right limbs, weakness for 1.5 years. Tendon micro-deviation to the left, left limb muscle strength Ⅴ level, right limb muscle strength Ⅳ level. CT: The left hydrocele increased and broadened, showing irregular cystic, beaded water-like density, thin wall, mainly in the left lateral fissure, part of the extension to the saddle pool, enhanced scan lesions were not seen Strengthen around the normal enhancement of blood vessels (Figure 1,2). Surgical findings: incision