Assessment of rates of lymph nodes and lymph node metastases in periprostatic fat pads in a consecutive cohort treated with retropubic radical prostatectomy.

Objective: To determine the rates of lymph nodes and lymph node metastases in periprostatic fat pads yielded during exposure of the anterior surface of the dorsal vein complex, puboprostatic ligaments, and endopelvic fascia during radical prostatectomy.

Methods: Histopathologic examination was performed in 356 patients who underwent radical prostatectomy between July 2010 and September 2010 at a single institution. Separate histologic work-up of the periprostatic fat pads addressed the presence of lymph nodes and possible metastatic invasion of lymph nodes within this area. Descriptive analyses and multivariable analyses to predict the presence of lymph node metastases within these fat pads were performed.

Results: Lymph nodes within periprostatic fat pads were detected in 19 (5.5%) patients. Among these patients, tumor infiltration was found in 4 (1.2%). Three of these 4 patients harbored lymph node metastases without any other lymph node metastasis during standard lymphadenectomy. No relationship was detected between the total number of lymph nodes removed and the detection of lymph nodes within periprostatic fat pads (P = .6).

Conclusion: Our analysis demonstrates that periprostatic fat pads harbor lymph nodes. No relationship between the presence of lymph node metastases in periprostatic fat pads and the presence of lymph node metastases in other areas was found. Similarly, no relationship exists between the presence of lymph nodes in this area and the total number of lymph nodes yielded in other lymphatic fields. Therefore, for guaranteeing precise lymph node staging, implementing routinely pathologic work-up of periprostatic fat pads yielded during radical prostatectomy should be considered.