title: Occult metastases in sentinel nodes of 200 patients with operable breast cancer.
abstract: BACKGROUND
  Up to 30% of patients with operable breast cancer and negative regional lymph nodes experience disease recurrence within 10 years. Serial sectioning and immunohistochemical staining of these nodes have revealed 9% to 30% occult metastases.
  
  
  METHODS
  Sentinel nodes from 200 patients with T1 and T2 invasive breast carcinoma were step-sectioned at 2- to 3-mm intervals, fixed in 10% formalin, and embedded in paraffin. Sections were taken from the face of the blocks and stained with hematoxylin and eosin (H&E). The blocks were then cut completely, and sections at .25-mm intervals were stained with cytokeratin and examined.
  
  
  RESULTS
  Tumor metastases were found in 34 patients when the sentinel nodes were examined at 2- to 3-mm intervals and in an additional 51 patients when the nodes were sectioned in their entirety at .25-mm intervals and stained with cytokeratin, bringing the total number of patients with metastases to 85. Of the 51 patients whose metastases were detected by 2- to 3-mm sectioning and cytokeratin staining, 27 had isolated tumor cells and 24 had clusters of innumerable malignant cells, all of which were visualized and confirmed by H&E staining of the adjacent sections.
  
  
  CONCLUSIONS
  Histologic examination of sentinel nodes of patients with invasive breast cancer sectioned at 2- to 3-mm intervals and stained with H&E significantly underestimates nodal metastases. Sectioning of the entire sentinel nodes at .25-mm intervals and staining with cytokeratin detects metastases as either isolated cells or as clusters.
authors.affiliation: Department of General Surgery, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA. kdowlat@rush.edu
authors.forename: K
authors.initials: K
authors.lastname: Dowlatshahi
authors.forename: M
authors.initials: M
authors.lastname: Fan
authors.forename: J M
authors.initials: JM
authors.lastname: Anderson
authors.forename: K J
authors.initials: KJ
authors.lastname: Bloom
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D002277:Carcinoma / Q000473:pathology* / Q000556:secondary* / Q000601:surgery; D046508:Culture Techniques; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*