A case report and literature review of heterotopic mesenteric ossification

Introduction and importance

Heterotopic mesenteric ossification is a benign bony tissue growth in the mesentery that mostly follows repetitive or severe abdominal injuries leading to reactive bone formation in the mesentery. There are only 73 cases (51 publications) identified in the literature up to the beginning of 2020.

Case presentation

45-year-old Saudi male underwent multiple laparotomies to manage complicated appendicitis which ended with a diverting ileostomy and a colostomy as a mucus fistula. After 9 months, the patient was admitted to the General Surgery department in Al-Hada Armed Forces Hospital for an open ileostomy and colostomy reversal surgery where several irregular bone-like tissues of hard consistency and sharp edges with some spindle-shaped structures resembling needles were found in the mesentery of the small intestine and histopathology revealed of trabecular bone fragments confirming the diagnosis.

Clinical discussion

The majority of cases occur mid to late adulthood with a predilection in the male gender, and usually present with bowel obstruction or an enterocutaneous fistula. Although it has no malignant potential, it may cause severe bowel obstruction that can lead to mortality, it's a rare occurrence and, therefore, is difficult to diagnose among many common abdominal disturbances.

Conclusion

Here we report a rare case of heterotopic mesenteric ossification, which should be considered as one of the delayed complications of abdominal surgery or trauma. The time range of expecting the presentation of heterotopic mesenteric ossification following major abdominal trauma or surgery should be extended and continuously considered during differential diagnosis.

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One of the delayed complications of abdominal surgery or trauma is Heterotopic mesenteric ossification.

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Since 1983 there are only 73 cases of Heterotopic mesenteric ossification published to date.

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Preoperative diagnosis of Heterotopic mesenteric ossification should be based mainly on the characteristic radiographic findings without relying on the levels of calcium or alkaline phosphatase.

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The only way to reach the definitive diagnosis is through excision and histopathological analysis.

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Heterotopic mesenteric ossification has no malignant potential, but it can cause severe bowel obstruction that can lead to mortality in already sick patients.

A case report of mesenteric heterotopic ossification: Histopathologic and genetic findings

Mesenteric heterotopic ossification (MHO) is very rare and occurs in mid- to late-adulthood, usually in the context of prior abdominal surgery. The mechanisms of MHO are unknown. Here we describe the case of a 72-year-old man with MHO. Standard histological staining revealed that MHO occurred through an endochondral process. By comparison to known mutations in genetic conditions of HO such as fibrodysplasia ossificans progressiva (FOP) and progressive osseous heteroplasia (POH), DNA sequencing analysis demonstrated the presence of a commonly occurring heterozygous synonymous polymorphism (c.690G>A; E230E) in the causative gene for FOP (ACVR1/ALK2). However, no frameshift, missense, or nonsense mutations in ACVR1, or in the causative gene for POH (GNAS), were found. Although genetic predisposition may play a role in MHO, our data suggest that mutations which occur in known hereditary conditions of HO are not the primary cause.