[Immunohistologic determination of a tumor marker (CEA) in diseases of the gastrointestinal tract].

CEA levels in serum are not reliable markers of tumors. In this paper a method for determination of this antigen for tissue sections is given. Histology, immunohistology and serum levels of CEA were compared. Tissue sections were obtained by surgical and endoscopic techniques. In several cases there was a discrepancy between serological and morphological results. Based on recent investigations elevated CEA levels might be only useful in reflecting a relapse of carcinoma of the colon. Immunohistological determinations were done by IFT and PAP-method. The results of both assay systems were comparable. CEA could be also detected in benign neoplasiogenic tissue, i.e. in tubular type of adenomatose polyps and in ulcerative colitis. Both diseases are known to become malignant at an high degree. By contrast no CEA could be detected in hyperplasiogenic polyps. Detection of CEA in malignant tissue might be useful for final classification of tumors. Occurrence of CEA in non malignant tissue should give rise to control in short regular intervals. Prospective studies might show the reliability of the CEA-bearing cells of non malignant tissue.