We report on three cases of ulcerative colitis who presented with increased levels of serum carcinoembryonic antigen (CEA) during the active stage. All cases were pancolitis with a moderate to severe disease course. After remission induction with medical therapies, serum CEA levels decreased to the normal reference range. Immunohistochemical analyses demonstrated the existence of CEA not only along with the apical surface of the colonic epithelia but also at the cytosol of the inflamed epithelia where goblet cells were depleted during the active stage. We speculate that CEA was up-regulated by inflammatory response particularly in the process of epithelial regeneration.
Keywords: Carcinoembryonic antigen; Ulcerative colitis.