title: Comparing the efficacy of routine H&E staining and cytokeratin immunohistochemical staining in detection of micro-metastasis on serial sections of dye-mapped sentinel lymph nodes in colorectal carcinoma.
abstract: BACKGROUND
  The significance of techniques used for detecting micro-metastasis (MM) or isolated tumor cells (ITCs) is a controversial issue among investigators. We evaluated the different techniques used on sentinel lymph node (SLN) to detect MM/ITCs.
  
  
  METHODS
  Ninety-one SLNs of 15 patients underwent serial section with 100 μm interval. In each level, two sections were prepared. One section was stained with H&E and another with anti-cytokeratin antibody (immunohistochemistry). Then the sections were evaluated for detecting MM/ITCs. Results were analyzed by chi-square test.
  
  
  RESULTS
  1656 sections of 91 SLNs of 15 patients were evaluated by a pathologist; MM was found in 1 and ITCs in 1 case. Overall, 2 out of 15 cases (13.3% of the patients) showed MM/ITCs by IHC staining. So, serial section along with using IHC was superior than serial section and routine H&E staining. But it did not affect the 5-year survival of the patients (P = 0.47).
  
  
  CONCLUSIONS
  Using the combined techniques of serial section and IHC staining could up-stage 13.3% of colon cancer patients who were lymph node negative. In other studies with different combination of serial section, IHC staining, and PCR, investigators were able to find MM/ITCs in 3-39% of the cases. In our study, although serial section and IHC staining could up-stage 13.3% of patients, it could not affect the 5-year survival of the patients.
authors.affiliation: Department of Pathology-Acquired Immunodeficiency Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Sanei
authors.affiliation: Department of General Surgery, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Seid Abbas
authors.initials: SA
authors.lastname: Tabatabie
authors.affiliation: Department of General Surgery, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Seid Mozafar
authors.initials: SM
authors.lastname: Hashemi
authors.affiliation: Department of Pathology, School of Medicine, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Cherei
authors.affiliation: Department of Pathology-Acquired Immunodeficiency Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Parvin
authors.initials: P
authors.lastname: Mahzouni
authors.affiliation: Department of General Surgery, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Behnam
authors.initials: B
authors.lastname: Sanei
keywords: Colorectal cancer; cytokeratin; immunohistochemistry; micro-metastasis; sentinel lymph node