A Case of a Fixed Giant Peritoneal Loose Body outside the Peritoneum and near the Rectovesical Excavation

A peritoneal loose body (PLB) is a tissue completely separated from other intraperitoneal organs. It is rare and usually found incidentally during laparotomy, examination, or autopsy. It is usually located free in the peritoneal cavity and does not exist in the extraperitoneal space. It is generally thought to originate from the epiploic appendices released into the abdominal cavity following ischemic necrosis. We report a case of a giant PLB outside the peritoneal cavity, adjacent to the rectovesical excavation, inan asymptomatic 83-year-old man who underwent evaluation for cholecystolithiasis, preoperatively. Computed tomography revealed a mass with well-defined margins in the rectovesical excavation, consisting of a calcified core and peripheral soft tissue measuring 60 mm in diameter; it did not seem to invade adjacent organs. Although there were no symptoms or tumor growth over time, for a definitive diagnosis, we scheduled a laparoscopic extraction. On laparoscopic exploration, a white oval mass was found in the rectovesical excavation; there was no invasion of adjacent organs. We diagnosed the patient with a giant PLB.Postoperative recovery was uneventful. Most PLBs are asymptomatic and do not require surgery except when symptomatic, large in size, or suspicious for malignancy. The PLB is rarely extraperitoneal and usually freely mobile; however, in our patient, it was fixed and outside the abdominal cavity, near the rectovesical fossa. Although it could not be diagnosed preoperatively as being extra-peritoneal, it showed the typical imaging findings of PLB; thus, it was possible to remove the mass laparoscopically without bowel resection.