Immunohistochemical Study of Carcinoembryonic Antigen in Mucinous Cystic Neoplasm of the Pancreas

Abstract

Pathologic and immunohistochemical studies of 13 patients with mucinous cystic neoplasm of the pancreas were performed in order to determine whether these lesions represent overt or latent malignancy. In 9 patients with mucinous cystadenoma, the foci of mucus-rich columnar epithelia formed the usual pattern of stratifications and papillary projections with a benign appearance and did not stain with mouse monoclonal antibody to CEA (CM-010, Mochida, Japan). In contrast, the foci of mucus-poor columnar epithelia which were in a focal distribution showed moderate to severe atypical hyperplasia and reacted strongly with anti-CEA in 6 of the 9 patients. In addition, areas of both noninvasive and invasive mucinous cystadenocarcinomas in 4 patients, which were composed primarily of mucus-poor columnar epithelia, showed diffuse cytoplasmic and/or apical reactivity with anti-CEA. Based on these results, we conclude that severe atypical epithelial hyperplasia composed primarily of mucus-poor columnar epithelia represents a precursor to mucinous cystadenocarcinoma, and, therefore, mucus-poor atypical epithelia may undergo malignant transformation.