Abstract

Mesenteric cysts are typically described as benign interabdominal lesions. Basically, mesenteric cysts are rare with an incidence rate of between one case per 27 000 to one case per 25 000. The etiology has not been clearly discovered yet. It can occasionally be asymptomatic or present with acute life-threatening manifestations such as acute abdominal emergency that occurs in 10 of cases. It can arise from any site on the gastrointestinal tract. When it manifests with right lower quadrant (RLQ) pain and tenderness, it is difficult to distinguish from appendicitis, especially when there are no definite diagnostic criteria. We reported the case of a 74-year-old man with RLQ pain and tenderness, nausea, anorexia, and leukocytosis. Considering Alvarado scores, he had a score of 6. Ultrasonography revealed hypoechoic cystic structure on RLQ with a size of 7.3 x 3.2 cm, with internal septi and also partial increased thickness of one intestinal loop. Ultrasonography of appendix showed thickening of appendiceal wall 4 mm in diameter. Because we suspected mesenteric cysts, but considering signs and symptoms and paraclinical data, we could not rule out appendicitis and decided to make a diagnostic laparatomy. On laparatomy, an ileal mesenteric mass was found and completely resected. The appendix was also resected. Although appendicitis cannot be ruled out, the appendectomy should be performed, even if the appendix does not have any inflammation grossly or when other pathologic problem was seen in abdominal cavity such as mesenteric cyst.