Carcinoembryonic antigen in cytological specimens of urothelial carcinoma.

A peroxidase-antiperoxidase (PAP) technique was developed for the detection of carcinoembryonic antigen (CEA) in urothelial transitional cells of 52 bladder cancer patients. The percentage of CEA-containing malignant cells varied from 10% to 100%. As a mean, 65% of the malignant cells stained for CEA, while the corresponding figure for benign-looking cells was 24%. The results were compared with cytological evaluations, flow cytophotometric results, and immunofluorescent (IF) staining for CEA. With increasing malignancy, more CEA was detected with the PAP technique, whereas the IF technique failed to show this trend. 18 of 20 malignant-tumors had an aneuploid DNA pattern. The two diploid cases were moderately well differentiated. Samples from bladders with heavy inflammation should be avoided in the PAP technique, since the unspecific staining of granulocytes disturbed a correct evaluation of the transitional cells. The PAP technique used on cytological material is recommended for antigen determinations, since good morphology is obtained.