Revisiting the enigma of a large symptomatic peritoneal loose body: a case report and critical literature review.

INTRODUCTION AND

IMPORTANCE

Peritoneal loose bodies (PLBs), also known as "peritoneal mice," are rare calcified structures found in the peritoneal cavity. Smaller PLBs are usually asymptomatic, while larger PLBs can sometimes lead to abdominal discomfort, urinary retention, or intestinal obstruction. Diagnostic imaging, particularly computed tomography scanning, identifies these centrally calcified soft tissue masses.

CASE PRESENTATION: A 55-year-old Indo-Aryan man with chronic constipation presented with signs of intestinal obstruction. Initial imaging suggested a mesenteric mass, leading to the suspicion of a desmoid tumor. However, repeat imaging revealed a well-defined lesion with altered attenuation and a central calcified area in the pelvis, displacing the rectum. Laparoscopic exploration confirmed the presence of a PLB (4 × 3 cm) along with multiple adhesions. Surgical removal of the PLB, along with cholecystectomy, was performed successfully. Histopathological analysis confirmed the diagnosis of a benign PLB.

CLINICAL DISCUSSION: Large PLBs pose a significant diagnostic dilemma, as they often mimic solid neoplasms such as desmoid tumors due to their size and mass effect. Accurate preoperative diagnosis relies heavily on recognizing the characteristic mobile, centrally calcified "egg-shell" appearance on CT imaging. Laparoscopic management is the preferred approach for both definitive diagnosis and treatment, offering superior recovery outcomes.

CONCLUSION

PLBs represent a diagnostic challenge due to their rarity and diverse clinical presentations. They should be considered in the differential diagnosis of abdominal masses, especially when imaging reveals a centrally calcified lesion.