[Diagnosis of early prostatic cancer. Correlation of in vitro echography and histopathologic mapping]

Sonographic detection of early prostatic carcinoma is based on the depiction of a hypoechoic focus. Thirty-seven correlations between in vitro sonographic patterns and pathologic mapping of prostatectomy specimens could be obtained in 26 patients. It was assumed that carcinomas smaller than 5 mm in diameter could not be visualized on sonography. Sonography identified 4 to 8 carcinomas greater than 5 mm in size (sensitivity, 50%). Of 18 hypoechoic foci, only 4 were carcinomas (positive predictive value, 22%). Among false positive results, 79% corresponded to normal prostatic tissue at pathology. The specificity of the hypoechoic focus as an indicator of cancer was 52% in this series. 36% of the carcinomas were located in the anterior half of the prostate. The carcinomas that were detected on sonography were all hypoechoic.