The sentinel node concept in endometrial cancer: histopathologic validation by serial section and immunohistochemistry.

BACKGROUND

The sentinel node (SN) is defined as the first node in the lymphatic system that drains a tumor site. If the SN is not metastatic, then all other nodes should also be disease-free. We used serial sections and immunohistochemical (IHC) staining to examine both SN and non-sentinel nodes (non-SNs).

PATIENTS AND

METHODS

Twenty-three patients (median age 69 years) with early endometrial cancer underwent a laparoscopic SN procedure based on a combined detection method, followed by complete laparoscopic pelvic lymphadenectomy. If the SN was free of metastasis by both hematoxylin and eosin (H&E) and IHC staining, all non-SNs were also examined by the combined staining method.

RESULTS

SNs were identified in 19 patients (82.6%). A total of 47 SNs were removed (mean 2.5). Ten SNs (21.3%) from five patients (26.3%) were found to be metastatic at the final histologic assessment. In 14 patients, no metastatic SN involvement was detected by H&E and IHC staining. In these 14 patients, 120 non-SNs were examined by serial sectioning and IHC, and none were found to be metastatic.

CONCLUSION

The SN procedure appears to reliably predict the metastatic status of the regional lymphatic basin in patients with early endometrial cancer.