title: Colorectal adenocarcinoma: quality of the assessment of lymph node metastases.
abstract: OBJECTIVE
  We have studied 193 cases of colorectal adenocarcinoma from a population-based register to determine the minimum number of lymph nodes to be examined to provide an accurate assessment of the presence of nodal metastases.
  
  
  METHODS
  The mean total number of lymph nodes identified per surgical specimen was 11 +/- 6.8 (range, 1-36) using traditional dissection. One hundred eighteen specimens (61 percent) were classified as Dukes B. Seventy-five (39 percent) had lymph node metastases (Dukes C) with a mean of 3.3 +/- 4.7 positive lymph nodes per specimen. With binomial distribution we calculate the probability to find at least one positive node in a sample size n with a determined proportion of positive nodes.
  
  
  RESULTS
  The error probability in the ganglionar assessment by traditional dissection was 0.05 with 6 examined lymph nodes and 0.01 with 10 examined nodes.
  
  
  CONCLUSIONS
  We must provide the pathologist with a minimum of six examined lymph nodes per surgical specimen for an optimal Dukes B assessment.
authors.affiliation: Department of Surgery, Faculty of Medicine, University of Cantabria, Santander, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Hernanz
authors.forename: S
authors.initials: S
authors.lastname: Revuelta
authors.forename: C
authors.initials: C
authors.lastname: Redondo
authors.forename: C
authors.initials: C
authors.lastname: Madrazo
authors.forename: J
authors.initials: J
authors.lastname: Castillo
authors.forename: M
authors.initials: M
authors.lastname: Gómez-Fleitas
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012042:Registries; D015203:Reproducibility of Results