Stage specific lymph node metastasis mapping in radical cystectomy specimens

Purpose: We provide an accurate map of lymph node (LN) metastasis in patients with bladder cancer undergoing radical cystectomy and pelvic lymph node dissection. Materials and Methods: We analyzed data on 176 consecutive patients operated on by the same surgeon. The extent of node dissection included presacral, bilateral common iliac and pelvic, and perivesical. The number of LNs removed from each site and the number of metastases bearing nodes were recorded separately. Stage specific maps were constructed. Results: The median number of LNs removed was 25 (range 2 to 80). Metastases were found in the lymph nodes of 43 patients (24.4%) and the median number of positive nodes was 3 (range I to 63). Of these patients 22 (51%) had lymph node involvement at more than 1 site. The mean number of positive/total LNs sampled +/- SD in LN positive cases was 26% +/- 28% and the median was 13% (range 1.9 to 100%). Only 1 of the patients with pT1 (3.6%) had LN metastases, which was in the pelvic region. Only 2 of the patients with pT2 (3%) had LN metastases outside of the true pelvis and perivesical sites. Of patients with pT3 or pT4 16% had LN metastases outside the common boundaries for standard LN dissection, namely the common iliac artery and at or above aortic bifurcation. Conclusions: We present a detailed map of regional LN involvement in patients treated with radical cystectomy and lymph node dissection for transitional cell cancer of the bladder. Extensive LN dissection is essential for the complete removal of disease and accurate staging.