title: The evolving role of axillary lymph node fine-needle aspiration in the management of carcinoma of the breast.
abstract: BACKGROUND
  Image-guided fine-needle aspiration (FNA) studies of axillary lymph nodes (LN) to evaluate breast carcinoma have shown high specificity but variable sensitivity. The purposes of this study were to evaluate the performance of axillary LN FNA depending on clinicoradiologic findings and to document how treatment varied according to FNA results.
  
  
  METHODS
  The study cohort consisted of consecutive axillary LN FNA cases over a 4-year period, in which subsequent treatment was known. Clinicoradiologic assessment was classified as "low suspicion" or "high suspicion" and cytopathologic findings as "positive," "negative," or "indeterminate". The test performance for each, using surgical pathology outcome as the "gold standard," was calculated. The impact of axillary LN FNA on subsequent management decisions was analyzed.
  
  
  RESULTS
  Of the 163 cases, axillary FNA was positive in 94 of 163 (58%), negative in 55 of 163 (34%), and atypical/nondiagnostic in 14 of 163 (8%). A clinicoradiologic assessment of "high suspicion" had a positive predictive value (PPV) of 88%, whereas a "low suspicion" assessment had a negative predictive value (NPV) of only 68%. In contrast, the PPV and NPV of axillary LN FNA were 98.7% and 81.8%, respectively. Whereas all of the FNA-nonpositive cases were managed surgically, surgery was deferred in 26 of 94 of the FNA-positive cases, including 11 cases of neoadjuvant treatment. Most of the remaining (65 of 68) FNA-positive patients were spared sentinel lymph node biopsy.
  
  
  CONCLUSIONS
  Image-guided LN FNA is highly sensitive and specific for lymph node involvement by breast carcinoma and plays a role both in sparing sentinel lymph node biopsy and in triaging cases for systemic therapy.
authors: Department of Pathology and Laboratory Medicine, Mount Sinai Hospital and University of Toronto, Toronto, Ontario, Canada. mchang2@mtsinai.on.ca
authors: Martin C
authors: MC
authors: Chang
authors: Pavel
authors: P
authors: Crystal
authors: Terence J
authors: TJ
authors: Colgan
mesh_terms: D001365:Axilla; D044963:Biopsy, Fine-Needle / Q000379:methods*; D001940:Breast / Q000473:pathology* / Q000601:surgery; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity