A Case Report of a Peritoneal Loose Body

Abstract

Peritoneal loose bodies (PLBs), also termed peritoneal mice, are rare benign free-floating intraperitoneal masses most commonly originating from torsion and auto-amputation of epiploic appendages. Progressive saponification, calcification, and concentric fibrous layering lead to their characteristic appearance. While most PLBs are small and asymptomatic, giant peritoneal loose bodies (>4 cm) are extremely rare and may produce pressure-related symptoms or mimic neoplastic lesions on imaging, resulting in diagnostic dilemmas. We report a 43-year-old male who presented with intermittent lower abdominal pain for three months. Contrast-enhanced computed tomography (CT) of the abdomen and pelvis revealed a well-defined, non-enhancing, calcified pelvic mass measuring 32 × 37 × 28 mm, located anterior to the urinary bladder. Diagnostic laparoscopy demonstrated a freely mobile, smooth, white, encapsulated, firm mass with a characteristic “boiled-egg” appearance, which was completely retrieved laparoscopically. Histopathological examination confirmed a peritoneal loose body composed of concentric hyalinized fibrous lamellae surrounding a central core of necrotic adipose tissue with dystrophic calcification. The postoperative course was uneventful, and the patient remained symptom-free during follow-up. Although rare, giant peritoneal loose bodies should be included in the differential diagnosis of calcified pelvic masses. Awareness of their characteristic imaging features and intraoperative findings is essential to avoid unnecessary radical surgical procedures. Laparoscopic removal offers both definitive diagnosis and curative treatment with minimal morbidity.