Peritoneal mice implicated in intestinal obstruction: Report of a case and review of the literature

BACKGROUND: Peritoneal loose bodies or "peritoneal mice" are asymptomatic and mostly found as "incidentalomas" during intraperitoneal surgery or at autopsy. Implication of these concretions in an acute abdomen is a rare clinical entity. CASE REPORT: We report the case of a 63-year-old man who presented with small bowel obstruction and two calcified concretions in his pelvis. A computerized tomography scan demonstrated two oval stones near the terminal ileal loop with lumenal compression of the distal small bowel. During laparotomy, two extralumenal glistening stones, measuring 5.8 x 4.5 x 3.7 cm and 5.2 x 4.5 x 3.7 cm, were recovered from the peritoneal cavity. Histologically, the wall showed concentric lamellar fibrosis and calcification, whereas the nucleus displayed the vestiges of membranous fat necrosis; all consistent with diagnosis of peritoneal loose body. All symptoms of bowel obstruction were relieved postoperatively, and the patient had an uneventful recovery. DISCUSSION: Peritoneal loose body is a histopathologic diagnosis, and most other differentials for calcified intraperitoneal masses can be ruled out during the histologic examination. Surgical removal is recommended because conventional cross-sectional imaging cannot accurately establish the diagnosis.