A 44-year-old man was referred to our hospital for further examination of a right abdominal tumor found on computed tomography (CT) after he complained of light abdominal pain. Contrast enhanced abdominal CT and magnetic resonance imaging revealed a multi-locular cystic mass in the mesenteric region of the ascending colon. This was diagnosed as a mesenteric cyst, and laparoscopic surgery was scheduled. Laparoscopic examination confirmed a transparent yellow multi-cystic tumor leading to the ascending colon. Laparoscopic right hemicolectomy was performed without rupturing the cyst, and a histopathological diagnosis of mesenteric lymphangioma of the ascending colon was made. After an uneventful postoperative course, the patient was discharged on the 7th postoperative day; there has been no recurrence since. It is important to remove mesenteric cysts without rupturing them or leaving any residual tissue. To the best of our knowledge, however, no resections of mesenteric lymphangiomas of the ascending colon in adults have been reported in the Japanese literature. Herein, we discuss previous studies and report the outcome in our patient.
