Heterotopic Mesenteric Ossification Following Intraabdominal Surgery

ABSTRACT

Heterotopic mesenteric ossification is a very uncommon disorder that is characterized by new bone formation in the mesentery, which does not normally undergo ossification. A 52-year-old female experienced a small bowel obstruction 12 days after a segmental resection of the small bowel following a trauma. A laparotomy was performed 16 days after the initial operation, and a 2 cm hard mass was detected in the small bowel mesentery, with severe fibrous adhesions around the mass, involving the jejunum, which required resection. Postoperatively, the patient developed an intraabdominal abscess, followed by intestinal fistulation. The patient gradually recovered by conservative management, and left hospital 70 days after the first operation. Microscopic examination of the mass showed well oriented trabeculae of the osseous tissue, osteoid formation, with fine calcification and osteoblastic activity, but there was no formation of mature lamellar bone or clear evidence of the "zone phenomenon" that is classically described in heterotopic ossification. These findings appeared consistent with an early stage of heterotopic ossification. The etiology and pathogenesis are unknown; the heterotopic mesenteric ossification was thought to be associated with the trauma (intraabdominal surgery). The previous literature on heterotopic mesenteric ossification is reviewed, and a new case reported.