Unexpected locations of sentinel lymph nodes in endometrial cancer.

Introduction: To evaluate the anatomical location of sentinel lymph nodes (SLN) following intra-operative cervical injection in endometrial cancer.

Methods: All consecutive patients with endometrial cancer undergoing sentinel lymph node mapping were included in this prospective study following intra-operative cervical injection of tracers. Areas of SLN detection distribution were mapped.

Results: Among 436 patients undergoing SLN mapping, there were 1095 SLNs removed, and 7.9% of these SLNs found in 13.1% of patients, were detected in areas not routinely harvested during a standard lymph node dissection. These included the internal iliac vein, parametrial, and pre-sacral areas. The SLN was the only positive node in 46.1% (15/36) of cases with successful mapping and completion lymphadenectomy, including 3 cases where the sentinel node in the atypical location was the only node with metastatic disease.

Conclusion: SLN mapping using intra-operative cervical injection is capable to map out areas not typically included in a standard lymphadenectomy. The sentinel node is the most relevant lymph node to analyze and may enable to discover metastatic disease in unusual areas.