Ex vivo sentinel lymph node biopsy in colorectal cancer: a feasibility study

J Surg Oncol. 2002 May;80(1):27-32; discussion 33. doi: 10.1002/jso.10091.


Background and objectives: Sentinel lymph node (SLN) biopsy may improve staging of colorectal cancer. We tested the feasibility of ex vivo SLN dissection.

Materials and methods: Patients undergoing resection of a primary colorectal cancer were included in this study. SLN identification involved ex vivo injection of 1 cc isosulfan blue dye subserosally in the colon or submucosally in the rectum on a separate field. SLNs were cut at 2 mm intervals. Three hematoxylin and eosin-stained (HE) sections were prepared in addition to a middle level for cytokeratin immunostaining.

Results: Twenty-six patients with varying tumor location and stage were enrolled and the SLN was identified in 88% (23/26) cases. Three failures occurred in patients with rectal cancer. The average number of SLN harvested was 2.5. The status of the nodal basin was accurately predicted in 91% (21/23) of patients. Two false negative sentinel lymph nodes were harvested in 2 of 3 patients with stage III/IV colorectal cancer. The SLN upstaged 2 patients as a result of HE stained step sections (n = 1) and immunostaining (n = 1).

Conclusions: This data suggests that ex vivo SLN biopsy is feasible in colorectal cancer. Although ex vivo SLN biopsy does not alter the lymphatic dissection, it may upstage a subset of patients. The ex vivo technique may be less applicable in rectal cancer and false negative results may occur.

Publication types

  • Review

MeSH terms

  • Colonic Neoplasms / pathology*
  • False Negative Reactions
  • Feasibility Studies
  • Humans
  • Immunohistochemistry
  • Neoplasm Staging
  • Rectal Neoplasms / mortality*
  • Rosaniline Dyes
  • Sentinel Lymph Node Biopsy / methods*


  • Rosaniline Dyes
  • iso-sulfan blue