Does anterior prostatic fat tissue removed during robotic radical prostatectomy contain any lymph nodes?

INTRODUCTION: We investigated whether anterior periprostatic fat (APPF) tissue removed during robotic radical prostatectomy (RARP) contains any lymph nodes (LNs). MATERIAL AND METHODS: APPF tissues removed during RARP in 129 patients were evaluated histopathologically. Correlation with postoperative pathologic stage was made. Patients with a history of previous prostate or bladder surgery and radiation therapy were excluded. RESULTS: Mean patient age, serum prostate specific antigen (PSA), prostate weight and body mass index (BMI) were 62.2 ±5.5 (range 45–74), 9.3 ±6.3 ng/dl (range 0.26-30.3), 60.3 ±27.2 grams (range 11.0–180) and 26.6 ±1.9 kg/m(2) (range 20.0–30.3), respectively. Overall, LNs in APPF tissues were detected in 14 (10.9%) patients with a mean LN yield of 1.1 ±0.7 LNs (range, 1–3). Among those found, no metastatic LN was detected. Of the patients with pT2a (n = 22), pT2b (n = 15), pT2c (n = 62) and pT3a (n = 21) disease, LNs in APPF tissues were detected in 1 (4.6%), 1 (6.7%), 11 (17.7%) and 1 (4.8%) patient in each group, respectively. Among the patients, LNs in APPF tissues were detected in 0 (0%), 5 (35.7%), 8 (57.1%) and 1 (7.1%) patients of underweight, optimal weight, overweight and obese patients due to body mass index, respectively. CONCLUSIONS: In our series, LNs were detected in around 10% of the patients. Therefore, this fat should, not be pushed back during RARP but should be removed and sent for pathologic evaluation. Although no metastatic LN was detected in our series, the presence of metastatic LNs might have an impact on the oncologic outcomes of the patients and warrants further research.