Giant peritoneal loose body in the pelvic cavity: report of a case.

This report describes a giant peritoneal loose body in the pelvic cavity. A 63-year-old man who was asymptomatic underwent a routine medical examination, which revealed a tumor in the pelvic space. Computed tomography and magnetic resonance imaging showed a smooth-surfaced mass with two marked calcifications in the central position. Preoperatively, we suspected a calcified leiomyoma originating from the wall of the sigmoid colon; however, at laparoscopic surgery we extracted a hard, egg-shaped mass 5 cm in diameter, with detached appendices epiploicae. Histological examination revealed that this peritoneal loose body was made up of thick layers of fibrous tissue with a few cellular components, and necrotic fat tissue in the central position. Small peritoneal loose bodies are occasionally found during laparotomy or autopsy, but such a large one is very unusual.