[Flow cytometric determination of DNA distribution patterns of malignant and benign tumors of the prostate (author's transl)].

56 samples of prostates, clinical suspected of being carcinomas, were examined by flow cytometry concerning their DNA distribution patterns. Carcinoma was diagnosed in 25 cases. All histologically benign samples showed a G1-fraction higher than 95%. Accordingly all cases with a G1-fraction lower than or equal to 95% were interpreted to be flow cytometrically positive (= malignant). The results of flow cytometric measurements essentially depend on the relation of the compounds of the sample--carcinomatous and normal tissue. Concerning the DNA distribution pattern, highly differentiated carcinomas do obviously not always differ from normal tissue. Hence they can escape from flow cytometric proof. An improvement of the flow cytometric distinction between histologically malignant and benign samples is achieved by the introduction of correction procedures for background and cell aggregations.