腹腔游离体（PLB）常在术中意外发现，因体积小、与原手术病灶无关联，长期未引起临床重视。近年来随着影像技术的进步，PLB检出率提高，发病率呈上升趋势，有症状的巨大型PLB个案报告逐渐增多。PLB的临床特点主要有3个：（1）活动度大；（2）无血液供应；（3）肿瘤标志物阴性。在CT不同层面，PLB的影像学表现各异，根据其中心最大直径断面表现，可将PLB大体归纳为4种类型：（1）二种密度结构；（2）三层密度结构；（3）多层密度结构；（4）混杂密度结构。根据PLB大体表面观可分为3种类型：（1）普通型，直径< 5.0 cm；（2）巨大型，直径为5.0~10.0 cm；（3）超大型，直径>10.0 cm。提高对PLB的认识及诊断水平，有助于正确选择处理方法：（1）体检偶然发现的普通型PLB可随访观察；（2）术中意外发现的PLB应顺便取出；（3）巨大型或超大型PLB，以及出现在消化道、泌尿系统等部位且伴有临床症状者，原则上应争取尽早手术。本文就PLB形成原因及病理、临床及影像学表现、诊断及鉴别诊断、治疗及预后诸方面研究进展作一综述。

Peritoneal loose body (PLB) is often found accidentally during surgery, but has not attracted general attention for a long time due to its characters of small size and no relationship with the original surgical lesion. In recent years, the incidence of PLB has been increasing. With the advancement of imaging technology, the detection rate of PLB has increased, and many large PLB cases with symptoms have been reported. There are three main clinical features of PLB: (1) high mobility; (2) no blood supply; (3) negative tumor markers. The images of PLB vary at different CT levels. According to its maximum central section, PLB can be roughly classified into four types: (1) two density structures; (2) three-layer density structure; (3) multi-layer density structure; (4) hybrid density structure. According to the gross appearances of PLB, it can be divided into three types: (1) general type with diameter < 5.0 cm; (2) giant type with diameter between 5.0 and 10.0 cm; (3) extremely large type with diameter > 10.0 cm. The diagnostic and therapeutic modality of PLB: (1) asymptomatic general type PLB accidentally discovered in physical examination can be left untreated and followed up; (2) PLB accidentally found during surgery should be retrieved; (3) giant or extremely large PLB presented with alimentary or urinary system symptoms should be removed surgically. This paper reviews the research progress in the formation cause, pathology, clinical and imaging manifestations, diagnosis and differential diagnosis, treatment and prognosis of PLB.