A nearly-missed peritoneal loose body.

Peritoneal loose bodies (PLBs) are rare lesions that are difficult to diagnose directly, often leading to clinical oversight due to this diagnostic challenge. This paper reports a case of a PLB incidentally discovered during retroperitoneoscopic adrenal cyst excision. Due to cyst calcification and the PLB's proximity to the cyst, it was nearly missed. It was ultimately completely removed after correlating the surgical specimen with repeated reviews of imaging data.Enhancing the diagnostic proficiency for PLBs facilitates early identification and intervention, thus providing valuable reference for clinical decision-making.