title: Method of specimen fixation and pathological dissection of colorectal cancer influences retrieval of lymph nodes and tumour nodal stage.
abstract: BACKGROUND
  There is now evidence that meticulous specimen dissection may 'upstage' around one-quarter of colorectal cancers from node negative to node positive, although there is much debate as to how to achieve this: some authors prefer fat clearance techniques while others have opted for more conventional lymph-node retrieval with manual specimen 'breadknifing' and lymph-node palpation. While fat clearance is probably the optimum technique, it is time-consuming, costly and does not provide rapid diagnostic results.
  
  
  METHODS
  A prospective pathological study of 50 colorectal cancer resections was conducted with 100 comparison cases, the study group receiving at least an additional 24-h fixation of the mesocolonic or mesorectal fat in 10% aqueous formaldehyde prior to specimen dissection.
  
  
  RESULTS
  The percentage of node-negative colorectal cancer was significantly lower in the study group compared with the matched comparison group: (18) 36% compared with (55) 55% of comparison cases.
  
  
  CONCLUSIONS
  Effective lymph-node retrieval techniques require mesocolic/mesorectal fat to be adequately fixed prior to pathological dissection. This study suggests that satisfactory lymph-node retrieval is possible without fat clearance, provided the mesenteric fat is suitably fixed prior to colorectal cancer specimen dissection.
authors.affiliation: Department of Pathology, Queen Alexandra Hospital, Cosham, Portsmouth, PO6 3LY, UK. david@poller.dmeon.co.uk
authors.forename: D N
authors.initials: DN
authors.lastname: Poller
mesh_terms: D001706:Biopsy; D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods*; D009367:Neoplasm Staging / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D013048:Specimen Handling / Q000379:methods; D016707:Tissue Fixation / Q000379:methods*