Large intestinal lymphocytic phlebitis and venulitis in chronic ulcerative colitis.

Colonic vasculitis is seen in Crohn's disease and as a component of primary systemic vasculitis. It has rarely been described in chronic ulcerative colitis. Here we report a case of ulcerative colitis with prominent transmural lymphocytic phlebitis and venulitis. Although this is, to our knowledge, the first description of such an association, its recognition is important if confusion with other entities is to be avoided. The etiology of the vascular changes is unclear but they may be a secondary phenomenon induced by antigens, toxins or cytokines draining from the inflamed mucosa.