title: Ex vivo sentinel lymph node mapping in laparoscopic resection of colon cancer.
abstract: OBJECTIVE
  The study examined the feasibility and potential benefit of ex vivo sentinel lymph node (SLN) mapping, including multilevel sectioning (MLS) and immunohistochemistry (IHC) in colon cancer patients undergoing laparoscopic colectomy. The secondary goals were (i) to identify patient and tumour characteristics that might influence the success of the SLN technique, (ii) to investigate the extent of lymphadenectomy required to encompass tumour-positive nonsentinel lymph nodes (NSLN) and (iii) to ascertain the association of SLN status with oncological outcomes.
  
  
  METHODS
  SLN mapping was performed after specimen extraction using 1% Isosulfan blue. The SLNs were analysed with H&E staining after MLS, and if negative, IHC was performed. NSLNs were grouped by distance either greater than or less than 4 cm from the tumour.
  
  
  RESULTS
  Seventy-one patients completed the study between 2003 and 2007. Using H&E with MLS, the accuracy of SLN mapping was 76%, sensitivity was 52% and the false-negative rate was 48%. Excluding patients with clinically positive lymph nodes resulted in a significant improvement in accuracy to 81% and decreased the false-negative rate to 30%. Furthermore, as the only positive NSLN > 4 cm from the tumour was grossly positive, SLN mapping with a 4-cm mesenteric cuff would have given 100% sensitivity in patients without macroscopically involved nodes.
  
  
  CONCLUSIONS
  SLN mapping may be of value in selected patients. It may be possible to accurately stage patients with a 4-cm cuff of mesentery, although further validation of this proposal is required.
authors.affiliation: Bon Secours Hampton Roads Health System, Suffolk, Virginia, USA.
authors.forename: E B
authors.initials: EB
authors.lastname: Rivet
authors.forename: M G
authors.initials: MG
authors.lastname: Mutch
authors.forename: J H
authors.initials: JH
authors.lastname: Ritter
authors.forename: A A
authors.initials: AA
authors.lastname: Khan
authors.forename: J S
authors.initials: JS
authors.lastname: Lewis
authors.forename: E
authors.initials: E
authors.lastname: Winslow
authors.forename: J W
authors.initials: JW
authors.lastname: Fleshman
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery; D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D005188:False Negative Reactions; D005260:Female; D006416:Hematoxylin; D006801:Humans; D007150:Immunohistochemistry; D010535:Laparoscopy; D016015:Logistic Models; D008137:Longitudinal Studies; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015203:Reproducibility of Results; D012394:Rosaniline Dyes; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D016896:Treatment Outcome
chemical_list: D004396:Coloring Agents; D012394:Rosaniline Dyes; C025484:iso-sulfan blue; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin