International Journal of Case Reports and Images, Vol. 10, 2019. ISSN: 0976-3198 Int J Case Rep Images 2019;10:101025Z01NA2019. www.ijcasereportsandimages.com Alenazi et al. 1 CASE REPORT PEER REVIEWED | OPEN ACCESS Laparoscopic excision of large mesenteric cyst from the small bowel mesentery in adult male patient Naif Abdullah Alenazi, Khaled S. Ahmed, Mohamed S. Essa, Wael I. Abusiam, Abdulbaset M. Al-Shoaibi ABSTRACT Introduction: A mesenteric cyst is a cystic lesion that arises in the mesentery of the gastrointestinal tract from the duodenum to the rectum but most commonly developed in the small bowel mesentery. They develop in both adults and children but usually diagnosed during the fifth decade of life. Case Report: A 31-year-old male presented to Emergency Department with left iliac fossa pain without any other associated symptoms. His medical, surgical and family history was not significant. No history of previous abdominal operation. Abdominal ultrasonography showed mass in right iliac. Computed tomography revealed a large rounded mesenteric cyst seen in the left lumbar region measuring 10x10x9 cm with thin enhancing wall. The mass was excised by laparoscopy with healthy margins and the specimen was sent for pathological examination. The histopathological findings were suggested of pseudocyst. Conclusion: A mesenteric cyst in adult is extremely rare benign intra-abdominal pathology. Surgical excision is optimal treatment of mesenteric cyst with either laparotomy or laparoscopy. Naif Abdullah Alenazi 1 , Khaled S. Ahmed 1 , Mohamed S. Essa 1 , Wael I. Abusiam 1 , Abdulbaset M. Al-Shoaibi 2 Affiliations: 1 Department of General Surgery, Prince Moham- med bin Abdulaziz Hospital, Riyadh, Saudia Arabia; 2 Depart- ment of Radiology, Prince Mohammed bin Abdulaziz Hospital, Riyadh, Saudia Arabia. Corresponding Author: Naif Abdullah Alenazi, Department of General Surgery, Prince Mohammed bin Abdulaziz Hospital, Riyadh, Saudia Arabia; Email: dr.naifalenazi@gmail.com Received: 26 February 2019 Accepted: 29 March 2019 Published: 30 April 2019 Keywords: Computed tomography, Laparoscopy, Mesenteric cyst, Pseudocyst, Ultrasonography How to cite this article Alenazi NA, Ahmed KS, Essa MS, Abusiam WI, Al-Shoaibi AM. Laparoscopic excision of large mesenteric cyst from the small bowel mesentery in adult male patient. Int J Case Rep Images 2019;10:101025Z01NA2019. Article ID: 101025Z01NA2019 ********* doi: 10.5348/101025Z01NA2019CR INTRODUCTION Mesenteric cysts are very rare mesenteric tumor that can occur at any age [1]. It was discovered by Benevenni 1507 with about 820 cases reported till now in the literature since then [2]. It is most commonly seen in children under the age of 10 and in adults usually presented in the fourth decade of life. According to Kurtzetal the incidence of mesenteric cyst is equal between males and females and also there was no difference according to race [3].Most of mesenteric cysts discovered by either physical examination or imaging but it can present with symptoms such as recurrent abdominal pain, nausea, anorexia, vomiting, and bowel habits changes. Although most mesenteric cysts are benign in nature, it occasionally leads to complications, such as volvulus and intestinal obstruction [4, 5]. CASE REPORT A 31-year-old male who presented with intra- abdominal swelling with non-specific symptoms. The patient was admitted to the Department of general