Transrectal ultrasound in the diagnosis of prostate cancer: location, echogenicity, histopathology, and staging.

Adenocarcinoma of the prostate produces specific ultrasonic findings that can be used in diagnosis. We have examined 211 patients using transrectal ultrasound in both the sagittal and axial planes. Thirty-three carcinomas were detected, and 31 histologically confirmed; 24 by needle biopsy, six by transurethral resection, one by total prostatectomy, and two by the demonstration of distant metastases. On ultrasound, all of the carcinomas were less echogenic than normal prostate. All appeared to originate in the peripheral zone of the prostate and produced asymmetry of the gland. The majority of carcinomas in this series showed capsular involvement and ten penetrated and extended beyond the prostatic capsule. The results of this series indicate that transrectal ultrasound can be used to detect cancer of the prostate gland. Ultrasound demonstrated the extent of tumor involvement and enabled accurate staging of these cancers.