title: Maximizing lymph node retrieval during surgical resection of Wilms tumor.
abstract: BACKGROUND
  Sampling lymph nodes (LNs) is independently associated with decreased recurrence and improved survival for Wilms tumor (WT). Despite sampling, we noted cases where a few or no LNs were identified after resection of WT. We hypothesized fewer LNs were identified when submitted en bloc with the tumor, compared with when submitted separately.
  
  
  METHODS
  We conducted a retrospective chart review from 2003 to 2012 of WT resection cases, examining the type of LN dissection, the specimens submitted to pathology, number of LNs evaluated, and complications associated with the procedure.
  
  
  RESULTS
  We identified 74 children with WT; 59 of 74 (79.7%) had unilateral disease and 15 of 74 (20.3%) had bilateral disease. With unilateral disease, more LNs were identified by separate versus en bloc sampling (5.2 ± 0.6 vs. 4.4 ± 1.2 nodes, p=0.61). Both the methods identified fewer LNs compared with en bloc+separate sampling (12.5 ± 2.7 nodes, p<0.001 and p=0.04, respectively). The majority of children with bilateral disease (10/15, 66.6%) did not have LN sampling intraoperatively. When submitted separately, 83.3 ± 3.8% of all LNs were identified in the separate specimen, and two en bloc specimens that were noted to have adenopathy intraoperatively had no LNs pathologically identified. Few cases had complications, which did not appear associated with LN sampling.
  
  
  CONCLUSIONS
  En bloc+separate sampling yields the most LNs during resection of WT. We recommend using this technique to facilitate the maximum number of LNs evaluated in WT. Low rates of LN sampling in bilateral disease may indicate decreased regard for sampling when tumor stage is already known.
authors.affiliation: Department of Surgery, University of Colorado School of Medicine, Aurora, Colorado, United States.
authors.forename: Camille Linick
authors.initials: CL
authors.lastname: Stewart
authors.affiliation: Department of Pediatric Surgery, Children's Hospital Colorado, Aurora, Colorado, United States.
authors.forename: Jennifer Lynn
authors.initials: JL
authors.lastname: Bruny
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D008197:Lymph Node Excision / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D009392:Nephrectomy; D012189:Retrospective Studies; D009396:Wilms Tumor / Q000473:pathology / Q000601:surgery*