© 2011 THE AUTHORS BJU INTERNATIONAL © 2 0 11 B J U I N T E R N A T I O N A L | 1 0 9 , 6 0 3 – 6 0 7 | doi:10.1111/j.1464-410X.2011.10336.x 603 2011 THE AUTHORS; BJU INTERNATIONAL 2011 BJU INTERNATIONAL Laparoscopic and Robotic Urology LYMPH NODES IN PERIPROSTATIC FAT YUH ET AL. Analysis of regional lymph nodes in periprostatic fat following robot-assisted radical prostatectomy Bertram Yuh, Huiqing Wu, Nora Ruel and Timothy Wilson City of Hope National Medical Center, Duarte, CA, USA Accepted for publication 16 March 2011 INTRODUCTION The most reliable and definitive means of staging lymph node involvement in prostate cancer remains dissection and removal of the pelvic nodes. Recently, increased attention to extending the limits of obturator node dissection to include the external and internal iliac nodes has been suggested. Although consensus has not been reached regarding when and how to proceed, the current recommendation is that an extended pelvic lymph node dissection is preferred because it provides enhanced staging [1]. However, even with an extended dissection, landing zones for prostate cancer can still be missed. During the anterior dissection of a radical prostatectomy, a shroud of lymphofatty tissue overlying the prostate that extends from the inner surface of the pubic bone towards the bladder is routinely encountered. This tissue is often excised to improve visualization and clearly expose the operative field. Robot- assisted laparoscopic pelvic lymph node dissection has been shown to be feasible with lymph node yields comparable to those for open dissection [2]. In addition, the three- dimensional magnification of the Da Vinci surgical robotic system (Sunnyvale, CA, USA) allows simple dissection of this fat away from the anterior prostate, apex, endopelvic fascia and bladder neck. We commonly perform excision of this tissue with pathological analysis because others have described the occasional presence of lymph nodes [3,4]. We surmised that regional lymph node removal could provide better oncological staging and define patients at greater risk for disease recurrence. Over a 6-month period we prospectively examined BJUI BJU INTERNATIONAL Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? A few publications have reported on the presence of lymph nodes in the anterior prostate lymphofatty tissue. This is important as increasing emphasis is placed on extending the overall limits of lymph node dissection in prostate cancer. For a large group of patients treated with robotic prostatectomy we continue to routinely remove and examine this tissue in order to provide additional staging information for patients. In a comprehensive cancer centre, the long-term oncologic ramifications of excising tumour containing lymph nodes will continue to be studied. OBJECTIVE • To determine the incidence and significance of lymph nodes in the anterior prostatovesicular lymphofatty tissue. PATIENTS AND METHODS • One hundred and twenty patients with clinically localized prostate cancer underwent robot-assisted laparoscopic radical prostatectomy with excision of anterior prostatovesicular tissue at a single institution over a 6-month period. • Tissue was sent for pathological analysis. • Separate pelvic lymph node dissection was carried out in moderate-risk and high- risk patients. RESULTS • A total of 20 out of 120 patients (16.7%) had lymph nodes in the anterior lymphofatty tissue. • Average lymph node number when present was 1.5 (one to three). • Pathological assessment of the lymph nodes revealed metastatic prostate cancer in 3 out of 120 (2.5%) patients, each of whom had adverse pathological features. • Patients with metastatic lymph nodes in the anterior tissue did not have cancer involvement of the pelvic lymph nodes. • Patients with lymph nodes found in the anterior lymphofatty tissue were slightly younger but were otherwise similar with respect to other demographics, prostate- specific antigen, biopsy Gleason score, clinical stage, pathological stage, pathological Gleason score, seminal vesicle invasion, and margin status. CONCLUSIONS • Anterior lymphofatty tissue overlying the prostate occasionally contains lymph nodes that can harbour malignant disease and routine excision may eradicate regional tumour burden. • Of patients with nodes, 15% were found to have malignant involvement. • The long-term impact on progression-free and overall survival requires further study. KEYWORDS lymph nodes, prostate cancer, robotics, prostatectomy