AB149. 50. Large inflamed mesenteric cyst in an Irish male: a case report

Background: Mesenteric cysts are rare intra-abdominal tumors. Since the first description by the Italian anatomist Benevenni in 1507, less than 1,000 cases have been reported. The incidence has been estimated to be 1/100,000 in the adult population and 1/20,000 in the pediatric population. Majority of cases are diagnosed incidentally during routine physical examination or imaging. They can however present with non-specific abdominal symptoms such as pain, nausea/vomiting, and change of bowel habit. They rarely present acutely with bowel obstruction, volvulus, torsion or shock. The lack of characteristic clinical and radiological features makes this condition difficult to diagnose.

Methods: We describe a case of a large inflamed mesenteric cyst in a 26-year-old Irish male.

Results: He presented with 3-day history of worsening generalized abdominal pain localizing to the left lower quadrant. The pain was associated with nausea and anorexia. Abdominal examination demonstrated generalized abdominal tenderness with guarding in the left-iliac-fossa. Laboratory investigations revealed C-reactive protein of 166 mg/L and white-cell-count of 11.2×10⁹/L. Computer tomography demonstrated a 6.2 cm thick-walled cyst within the left flank at the level of the aortic bifurcation. The patient underwent a laparotomy and complete enucleation. He made an uneventful postoperative recovery and discharged home on day-5. Histologic examination confirmed a primary mesenteric cyst with inflammation.

Conclusions: Primary mesenteric cysts are rare and should be considered in the differential diagnosis in patients presenting with worsening abdominal pain and distension. Contemporary appraisal of the mesenteric organ now provides us with an opportunity to understand disease states involving the mesentery.

Keywords: Mesenteric cyst; mesentery; enucleation