Impact of separate versus en bloc pelvic lymph node dissection on the number of lymph node's retrieved in cystectomy specimens

Purpose: Pelvic lymphadenectomy during radical cystectomy yields a various number of lymph nodes depending on the extent of lymph node dissection and pathologist aggressiveness when searching the specimen. How the surgeon submits lymph nodes for pathological evaluation may also affect how many are retrieved. Materials and Methods: Bilateral pelvic lymph node dissection and radical cystectomy for transitional cell carcinoma of the bladder was performed in 32 patients. The extent of lymph node dissection involved standard and extended lymphadenectomy in 20 and 12 cases, respectively. In patients who underwent standard dissection unilateral en bloc submission of the lymph nodes was done with the contralateral lymph node dissection sent as an individual discrete packet. In those who underwent extended dissection all lymph nodes from each side were submitted en bloc or as 6 packets. Results: Standard lymphadenectomy en bloc specimens yielded a mean of 2.4 lymph nodes compared with 8.5 retrieved from individual lymph node specimens (p = 0.003). Extended lymphadenectomy en bloc specimens yielded a mean of 22:6 lymph nodes compared with 36.5 retrieved from the individually submitted packets (p = 0.02). Conclusions: Submitting pelvic lymph nodes as separate specimens optimizes pathological evaluation of the number of lymph nodes that may be involved with metastatic cancer. Such information is important for identifying patients who may benefit from adjuvant chemotherapy.