[Histochemical demonstration of CEA in pathology of the colorectum]

The evaluation of CEA serum levels and CEA tissue staining is one of the most common parameters used to help in the diagnosis and prognosis of colon-rectum disease. To this aim, an immunohistochemical demonstration of the CEA was carried out with the ABC staining system in sections of normal and diseased colon. 24 patients with polyps of the large intestine, 17 with rectocolitis, 22 with colon-rectum cancer and 11 normal subjects were studied. Results were positive in 9, 1% of the normal mucosa, 37, 5% of the polyps, 41, 2% of the rectocolitis and 100% of the carcinomas. However, the CEA in the positive reactions showed different degrees of staining and different cellular localization. From our results it would appear that the intracellular localization of this marker is connected with the degree of atypia in the histological sections. Immunohistochemical localization of the CEA could therefore be useful, above all in assessing the prognosis of colon-rectum disease.