**[1064] Seeking Standard for Adequate Pathological Lymph Node Staging in Bladder Carcinoma***Lu Wang, Kumaran Mudaliar, Vikas Mehta, Guliz A Barkan, Maria M Picken. Loyola University Medical Center, Maywood, IL***Background:** Lymph node (LN) metastasis is critical in tumor staging and prediction of disease recurrence after radical cystectomy among the patients with urothelial carcinoma of the bladder. Extended pelvic lymphadenectomy is part of standard procedure during radical cystectomy. In contrast to the cancer of other organ system (such as colon), there is no concensus regarding the requirement for minimum lymph nodes number submitted for pathologic evaluation. Our aim was to evaluate the adequacy of pathologic LN staging in radical cystectomy specimen.**Design:** All radical cystectomies performed over a 5-year period in our institution were reviewed, with particular attention paid to the total lymph node number, positive lymph nodes' number and their location, as well as the relation to lymphovascular invasion.**Results:** A total of 249 radical cystectomies with 8376 LN were reviewed. In 62 cases, a total of 278/1100 (25.2%) positive LN were identified. Among the positive cases, the average number of LN examined was 32.9 with an average number 3.71 positive LNs per case (11.2%). The highest % of positivity was seen among the peri-aortic LN (40.4%); while the common iliac LN were positive in 32.7%, and the hypogastric/obturator LN in 32.2%. The most commonly evalulated LN were the obturator (31.9%), external iliac (19%) and common iliac LN (15.5%).

Among the cases with positive lymph nodes, 56.5% had evidence of lymphovascular invasion, in contrast to 15.5% in cases with negative lymph nodes.**Conclusions:** Since the postive LN rate is 11.2%, ten LNs must be submitted to yield one positive lymph node. According to the 7th edition of the AJCC Cancer Staging Manual, pN1 represents one positive regional LN and pN2 represents multiple positive lymph regional lymph nodes. Thus, at least 20 lymph nodes should evaluated for adequate lymph node staging. Since, for pN3 staging a common iliac LN is required, this LN should also be evaluated.

Category: Genitourinary (including renal tumors)**Monday, March 4, 2013 9:30 AM****Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 164, Monday Morning**