title: Improved detection of metastases by step sectioning and immuno-histochemical staining of axillary sentinel nodes in patients with breast carcinoma.
abstract: BACKGROUND
  The object of this study was to examine whether a new protocol including step-sectioning and immunohistochemistry (IHC) staining of axillary sentinel nodes (SN) would lead to detection of more metastases in patients with breast cancer.
  
  
  METHODS
  Sixty-nine tumor free sentinel lymph nodes were examined. Step frozen sectioning was performed on formalin fixed SN and stained both by hematoxylin and eosin (H and E) and cytokeratin markers using IHC. Any tumoral cell in IHC stained slides were considered as a positive result. Metastases up to 0.2 mm were considered as isolated tumor cells and 0.2 up to 2 mm as micrometastasis.
  
  
  RESULTS
  Mean age of the patients was 48.7±12.2 years. Step sectioning of the SN revealed 11 involved by metastasis which was statistically significant (p<0.001). Furthermore, 15 (21.7%) of the patients revealed positive results in IHC staining for pan-CK marker and this was also statistically significant (p=0.001). Ten patients had tumoral involvement in lymph nodes harvested from axillary dissection and 4 out of 15 lymph nodes with positive result for CK marker were isolated tumor cells. However, 4 of 10 patients with tumor positive lymph nodes in axillary dissection were negative for CK marker and in contrast 6 of the pan-CK positive SN were in patients with tumor-free axillary lymph nodes.
  
  
  CONCLUSIONS
  Both IHC and step sectioning improve the detection rate of metastases. Considering the similar power of these two methods, we recommend using either IHC staining or step sectioning for better evaluation of harvested SNs.
authors.affiliation: Department of Pathology, Iran Cancer Institute, Emam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran E-mail : fensani@gmail.com.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Ensani
authors.forename: Ladan
authors.initials: L
authors.lastname: Enayati
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Rajabiani
authors.forename: Ramesh
authors.initials: R
authors.lastname: Omranipour
authors.forename: Nasrinalsadat
authors.initials: N
authors.lastname: Alavi
authors.forename: Sara
authors.initials: S
authors.lastname: Mosahebi
mesh_terms: D001365:Axilla / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000473:pathology*; D008875:Middle Aged; D009367:Neoplasm Staging; D013194:Staining and Labeling / Q000379:methods