title: Pathologic evaluation of axillary dissection specimens following unexpected identification of tumor within sentinel lymph nodes.
abstract: BACKGROUND
  Axillary lymph node dissection has been the standard of care after identification of a positive sentinel lymph node for breast cancer patients.
  
  
  OBJECTIVE
  To determine the likelihood of non-sentinel lymph node involvement for patients with negative sentinel node by frozen section, who are subsequently found to have tumor cells in the sentinel node by permanent section levels and/or cytokeratin immunohistochemistry.
  
  
  METHODS
  One hundred three patients with invasive breast cancer exhibiting negative frozen section evaluation of their sentinel node, but later found to have isolated tumor cells (n  =  46), micrometastasis (n  =  46), or metastases (n  =  11) in their sentinel node by permanent sections or immunohistochemistry, were enrolled in this prospective cohort study and underwent completion axillary dissection.
  
  
  RESULTS
  Six of 46 patients (13%) with isolated tumor cells in their sentinel node, 15 of 46 patients (33%) with micrometastasis in their sentinel node, and 2 of 11 patients (18%) with metastasis in their sentinel node had additional findings in the nonsentinel nodes. These findings resulted in a pathologic stage change in 2 patients. Predictors of positive nonsentinel nodes were 2 or more positive sentinel nodes (P  =  .002), sentinel nodes with micrometastasis versus isolated tumor cells (P  =  .03), and those with angiolymphatic invasion (P  =  .04).
  
  
  CONCLUSIONS
  Our findings lend support to axillary node dissection for patients with micrometastasis or metastasis in their sentinel nodes. However, studies with clinical follow-up are needed to determine whether axillary node dissection is necessary for patients with isolated tumor cells in sentinel nodes.
authors.affiliation: Department of Surgery, University of Minnesota Medical Center, Fairview, MN, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Gutierrez
authors.forename: Daniel
authors.initials: D
authors.lastname: Dunn
authors.forename: Margit
authors.initials: M
authors.lastname: Bretzke
authors.forename: Eric
authors.initials: E
authors.lastname: Johnson
authors.forename: John
authors.initials: J
authors.lastname: O'Leary
authors.forename: Diane
authors.initials: D
authors.lastname: Stoller
authors.forename: Sally
authors.initials: S
authors.lastname: Fraki
authors.forename: Leslie
authors.initials: L
authors.lastname: Diaz
authors.forename: Tamera
authors.initials: T
authors.lastname: Lillemoe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D011446:Prospective Studies; D021701:Sentinel Lymph Node Biopsy