膈下段腔静脉旁局限性脂肪积聚(Fat collection adjaction to subdiaphragmatic inferior vena cava)是指膈下段下腔静脉(IVC)周围脂肪组织肿块样堆积并压迫IVC，一般认为是一种正常变异，有关其检出率、与慢性肝病的关系和肥胖的关系，以 及形成机制的观点不尽相同。与局部脂肪异常沉积、增生或邻近脂肪迁移有关。
Paracaval lipoma can be a frequent finding on CT and can seen in up to 0.5% of examinations . It occurs at the medial aspect of the intrahepatic portion of the inferior vena cava (IVC) above the caudate lobe and represents pericaval fat appearing to invaginate into the IVC. This is thought to be due to volume averaging through inwards and upwards in-drawing of the posteromedial wall of the IVC as a result of negative pressure created within the thorax on inspiration .It is often seen in patients with cirrhosis （最常见于肝硬化病人）。