Identifying additional lymph nodes in radical cystectomy lymphadenectomy specimens

Lymph node count has prognostic implications in bladder cancer patients who are treated with radical cystectomy. Lymph nodes that are too small to identify grossly can easily be missed, potentially leading to missed nodal metastases and inaccurate nodal counts, resulting in inaccurate prognoses. We investigated whether there is a benefit to submitting the entire lymph node packet for histological examination to identify additional lymph nodes. We prospectively assessed 61 pelvic lymphadenectomy specimens in 14 consecutive patients undergoing radical cystectomy. The specimens were placed in Carnoy's solution overnight, then analyzed for lymph nodes. The residual tissue was entirely submitted to assess for additional lymph nodes. In 61 specimens, we identified 391 lymph nodes, ranging from 4-44 nodes per patient. We identified 238 (61%) lymph nodes with standard techniques and 153 (39%) lymph nodes in submitted residual tissue. The number of additional lymph nodes found in the residual tissue ranged from 0 to 26 (0-75%) per patient. These lymph nodes ranged in size from 0.05 to 1 cm. All additional lymph nodes were negative for metastatic disease. Submitting the entire specimen for histological examination allowed for identification of more lymph nodes in radical cystectomy pelvic lymphadenectomy specimens. However, as none of the additional lymph nodes contained metastatic disease, it is unclear if there is a clinical benefit in evaluating lymph nodes that are neither visible nor palpable in lymphadenectomy specimens. Modern Pathology (2012) 25, 140-144; doi:10.1038/modpathol.2011.137; published online 9 September 2011