Role of transrectal ultrasound in the diagnosis of extracapsular prostate cancer.

Introduction: Transrectal ultrasound (TRUS) has significantly improved the diagnostic rate, nevertheless, the correlation between findings on TRUS and clinically significant prostate cancer (PCa) is not completely understood. The purpose of this study was to evaluate the diagnostic accuracy and utility of preoperative TRUS in patients with PCa to define the sonographic signs of cohesion of the Denonvilliers' fascia (DF) to prostate capsula (PC) to detect the local advancement of the disease.

Methods: Between April 2010 and May 2013, at our Department of Urology, the clinical anatomy of preoperative regions and excised specimens was reviewed macroscopically for 68 cases of radical retropubic prostatectomy for PCa and compared to ultrasound images obtained by TRUS.

Results: Pathological analysis detected on the surface of the prostate the DF fused with the PC at the midpoint of the prostatic posterior surface in 94 % of the cases, in 4 % the DF remained at a certain distance from PC in this region and in 1 case lateral pelvic fascia fused with PC and little adipose tissue was present between them (P < 0.005). The TRUS allowed a more precise result in terms of tumor extension to DF with a detection rate of 95 %. (P < 0.001).

Conclusion: In our opinion, it is very important to recognize preoperatively the possibility of cancer extracapsular extension to the DF and to the rectum wall, using a simple and low cost examination as TRUS. The knowledge of the fascial structures anatomy around the prostate is necessary to perform a nerve-sparing radical prostatectomy, avoiding excessive bleeding, iatrogenic positive surgical margin, and post-operative complications.