title: The nodal location of metastases in melanoma sentinel lymph nodes.
abstract: BACKGROUND
  The design of melanoma sentinel lymph node (SLN) histologic protocols is based on the premise that most metastases are found in the central parts of the nodes, but the evidence for this belief has never been thoroughly tested.
  
  
  METHODS
  The nodal location of melanoma metastases in 149 prospectively analyzed, completely step sectioned, positive SLNs from 96 patients was examined using 3 theoretical protocols, evaluating respectively: (1) the 3 most central step sections only; (2) the 3 most peripheral step sections only; and (3) 3 step sections evenly distributed throughout the individual SLNs. In addition, the size of the metastases located exclusively outside the 2 regional protocols (ie, 3 central sections, and 3 peripheral sections) were measured and compared with each other.
  
  
  RESULTS
  The metastasis detection rates of the central, the peripheral, and the evenly distributed protocols were 77%, 79%, and 78%, respectively. No difference in either the mean volume or the maximum diameter of the metastases located exclusively outside the central and the peripheral protocols was found (volume: 0.036 vs. 0.031 mm and diameter: 0.320 vs. 0.332 mm).
  
  
  CONCLUSIONS
  In SLNs, melanoma metastases are located throughout the nodes. Metastases located exclusively outside the peripheral or the central protocol are equally sized. Complete step sectioning of all SLNs will ensure both high metastasis detection rates and detection of all large metastases, and allow for performance of unbiased size estimates.
authors.affiliation: Institute of Pathology, Aarhus University Hospital, Aarhus, Denmark. rikrib@rm.dk
authors.forename: Rikke
authors.initials: R
authors.lastname: Riber-Hansen
authors.forename: Jens Randel
authors.initials: JR
authors.lastname: Nyengaard
authors.forename: Stephen Jacques
authors.initials: SJ
authors.lastname: Hamilton-Dutoit
authors.forename: Torben
authors.initials: T
authors.lastname: Steiniche
mesh_terms: D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008207:Lymphatic Metastasis / Q000473:pathology*; D008545:Melanoma / Q000473:pathology*; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology*