title: Lymphadenopathy: defining a palpable lymph node.
abstract: BACKGROUND
  The threshold size required to detect lymphadenopathy via palpation has never been formally determined. The purpose of this study was to determine the threshold, sensitivity, and error of node palpation and how this changes with experience.
  
  
  METHODS
  Lymphadenopathy models were created using polyvinyl alcohol cryogel (PVA-C) to mimic tissue tactility. Node diameter ranged from 0.5 to 4 cm. Study subjects were medical students, otolaryngology residents, and otolaryngology consultants. Each subject provided 22 estimates of size. Primary outcomes were the sensitivity, error (true vs estimated size), and threshold of palpation.
  
  
  RESULTS
  Thirty subjects completed the study. Sensitivity was 60%, 74%, and 86% for students, residents, and consultants, respectively (p < .01). Error was 0.88 cm, 0.61 cm, and 0.57 cm, respectively (p < .05). Palpation threshold was 1.32 cm, 0.83 cm, and 0.75 cm, respectively (p < .05). All participants detected nodes ≥2 cm, whereas consultants detected nodes ≥1 cm.
  
  
  CONCLUSIONS
  Experience is associated with decreased palpation threshold and error, and increased sensitivity. Educational interventions should target nodes <2 cm.
authors.affiliation: Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Xu
authors.forename: Gordon
authors.initials: G
authors.lastname: Campbell
authors.forename: Hussain
authors.initials: H
authors.lastname: Alsaffar
authors.forename: Michael G
authors.initials: MG
authors.lastname: Brandt
authors.forename: Philip C
authors.initials: PC
authors.lastname: Doyle
authors.forename: Jordan T
authors.initials: JT
authors.lastname: Glicksman
authors.forename: Kevin
authors.initials: K
authors.lastname: Fung
mesh_terms: D002983:Clinical Competence; D005180:Faculty, Medical; D006801:Humans; D007396:Internship and Residency; D008198:Lymph Nodes; D008206:Lymphatic Diseases / Q000175:diagnosis*; D008953:Models, Anatomic; D010173:Palpation; D015203:Reproducibility of Results; D013337:Students, Medical
keywords: lymph node palpation; medical education; physical examination; simulation