title: Determinants of False-Negative Fine-Needle Aspirates of Axillary Lymph Nodes in Women with Breast Cancer: Lymph Node Size, Cortical Thickness and Hilar Fat Retention.
abstract: OBJECTIVE
  Ultrasound-guided fine-needle aspiration (UG-FNA) is utilized to sample axillary lymph nodes in breast cancer patients. Diagnostic sensitivity is good but few data exist regarding the causes of false-negative results.
  
  
  METHODS
  Fifty-four UG-FNAs of sentinel lymph nodes with histologic follow-up were identified. Gross and radiographic lymph node size, the percentage replaced by carcinoma and the cortical thickness were correlated with false-negative rates.
  
  
  RESULTS
  Thirty-seven aspirates were negative, 5 of these being false-negative (9%). True-positive lymph nodes averaged 1.3 cm in dimension while false-negatives averaged 0.92 cm. Percentage involvement by carcinoma for true-positive FNAs averaged 69% while false-negatives averaged 25%. Cortical thickness averaged 5.6 mm in true-positive FNAs but 2.9 mm in false-negatives.
  
  
  CONCLUSIONS
  A relationship exists between lymph node size and the likelihood of a false-negative FNA. Lymph nodes <1.2 cm have a higher incidence of false-negative results. Lymph nodes with <30% involvement demonstrated a higher percentage of false-negatives than those with >30% replacement. Sentinel lymph nodes <1 cm appear to be relatively poor candidates for UG-FNA. Lymph nodes with a cortical thickness <3.5 mm are more often associated with a false-negative result than nodes with a thicker cortex.
authors.affiliation: Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Mo., USA.
authors.forename: D Eric
authors.initials: DE
authors.lastname: Ewing
authors.forename: Lester J
authors.initials: LJ
authors.lastname: Layfield
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Joshi
authors.forename: Mark D
authors.initials: MD
authors.lastname: Travis
mesh_terms: D001365:Axilla; D044963:Biopsy, Fine-Needle / Q000379:methods; D001943:Breast Neoplasms / Q000473:pathology*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D021701:Sentinel Lymph Node Biopsy / Q000379:methods; D018084:Ultrasonography, Interventional / Q000379:methods