biostudies-literatureUnknown15(9)Mayfield JPeritoneal loose bodies (PLBs) have been sparingly documented within the surgical and radiologic literature, with 38 cases reported to date. A 67-year-old male presented to urology for the management of an asymmetric prostatic nodule. Imaging incidentally identified a well-circumscribed mass of low T2 signal intensity with a small fatty core in the left lower quadrant close to the sigmoid colon; malignancy was in the differential. The mass grew slightly over the next year. A diagnostic laparoscopy retrieved a free floating 4 × 4 cm benign mass from the pelvis, identified as necrotic fat with areas of dystrophic calcifications. PLBs are often a diagnostic dilemma without surgical intervention. Here we present a diagnostic algorithm based on a comprehensive literature review and our case to Radiology case reports1506-1511https://www.ebi.ac.uk/biostudies/studies/S-EPMC7339014biostudies-literaturePeritoneal loose bodies and the differentiation of fatty abdominal and pelvic lesions.PMC7339014Mayfield JSchammel DPYurko YSchammel CDevane AMfalsePeritoneal loose bodies and the differentiation of fatty abdominal and pelvic lesions.Peritoneal loose bodies (PLBs) have been sparingly documented within the surgical and radiologic literature, with 38 cases reported to date. A 67-year-old male presented to urology for the management of an asymmetric prostatic nodule. Imaging incidentally identified a well-circumscribed mass of low T2 signal intensity with a small fatty core in the left lower quadrant close to the sigmoid colon; malignancy was in the differential. The mass grew slightly over the next year. A diagnostic laparoscopy retrieved a free floating 4 × 4 cm benign mass from the pelvis, identified as necrotic fat with areas of dystrophic calcifications. PLBs are often a diagnostic dilemma without surgical intervention. Here we present a diagnostic algorithm based on a comprehensive literature review and our case to 2020-01-01T00:00:00Z2020 Sep2025-05-29T19:52:43.114Z2025-05-29T19:52:43.114ZS-EPMC73390143267045010.1016/j.radcr.2020.06.040