title: Extensive pathological analysis of selected melanoma sentinel lymph nodes: high metastasis detection rates at reduced workload.
abstract: BACKGROUND
  Extensive pathological workup of sentinel lymph nodes (SLNs) in melanoma detects more patients with metastasis-positive SLNs than do routine protocols, but at the cost of high laboratory workloads. We aimed to design a protocol that reduced this workload without compromising metastasis detection.
  
  
  METHODS
  We analyzed 920 SLNs from 321 consecutive patients with melanoma by complete step sectioning and immunohistochemistry. We designed different models to theoretically reduce the number of histological sections examined and compared the results from these simulations with results obtained with our extended protocol, with the restricted national Danish protocol, and with the protocol recommended by the European Organization for Research and Treatment of Cancer (EORTC).
  
  
  RESULTS
  The extended protocol increased the metastasis detection rate by 22% (95% confidence interval, 11-34; 30.8% vs. 25.2%, P < .0001) compared with the national Danish protocol, and it had a similar rate to that reported by the EORTC (30.8% vs. 29.4%, P = .6229). The workload associated with complete step sectioning could be reduced by 40% by focusing step sectioning on the SLNs with the highest gamma counts, while examining SLNs with lower gamma counts with one to three central sections. The false-negative rate for detecting metastases with this reduced protocol was 6% compared with complete step sectioning.
  
  
  CONCLUSIONS
  Combining complete step sectioning of SLNs with immunohistochemistry ensures high metastasis detection rates. Workloads can be markedly reduced with only a slight increase in the false-negative rate by focusing analysis on the SLNs most likely to contain metastases, i.e., those with the highest gamma counts.
authors.affiliation: Institute of Pathology, Aarhus University Hospital, Noerrebrogade 44, Aarhus C, 8000, Denmark. rrhan@as.aaa.dk
authors.forename: Rikke
authors.initials: R
authors.lastname: Riber-Hansen
authors.forename: Pia
authors.initials: P
authors.lastname: Sjoegren
authors.forename: Stephen Jacques
authors.initials: SJ
authors.lastname: Hamilton-Dutoit
authors.forename: Torben
authors.initials: T
authors.lastname: Steiniche
mesh_terms: D000951:Antigens, Neoplasm / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D005720:Gamma Rays; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D058965:MART-1 Antigen; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D009418:S100 Proteins / Q000378:metabolism; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D013668:Technetium Tc 99m Aggregated Albumin
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins; D019275:Radiopharmaceuticals; D009418:S100 Proteins; D013668:Technetium Tc 99m Aggregated Albumin