Possible Contribution of a Diverticulum to the Development and Rupture of Colonic Lymphangioma.

A 55-year-old Japanese man with a history of diverticulitis underwent colonoscopy for careful evaluation of progressive anemia. A 5-mm depressed lesion oozing spontaneously was observed at the hepatic flexure. On suspicion of depressed-type of cancer, right-sided hemicolectomy was performed. Histopathological examination indicated a collapsed lymphangioma exactly over a diverticulum, which had previously been complicated diverticulitis. The colonic mucosa and lymphangioma prolapsed beyond the subserosal layer via the muscularis propria defect, resulting in a depressed lesion and mucosal laceration with hemorrhage. This case suggests the contribution of a colonic diverticulum to the development and rupture of lymphangioma, which needed to be distinguished from depressed-type colon cancer.