Purpose: Surgical staging in endometrial cancer has evolved and sentinel lymph node (SLN) mapping has replaced a full pelvic and paraaortic lymphadenectomy in several cases. An intraoperative evaluation of SLN might identify patients who could benefit the most from a full lymphadenectomy. The aim of this study is to evaluate the clinical relevance of frozen section of SLN.
Methods: A retrospective analysis in patients with endometrial cancer who underwent SLN mapping with intraoperative evaluation at frozen section between February 2016 and September 2019 was performed. In case of metastatic involvement, a full lymphadenectomy was performed.
Results: Fifty-eight patients met the inclusion criteria. Clinical-pathologic characteristics of the patients and surgical data were analyzed. Overall, bilateral and unilateral detection rates were 100% (58/58), 89.7% (52/58), and 10.3% (6/58), respectively. Eight patients had a stage IIIC disease at permanent section. Frozen section detected SLN metastases in four of eight patients. Of these, two were micrometastases and two were macrometastases. At frozen section of the SLNs, no macrometastases were misdiagnosed. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of frozen section in detecting metastases was 50%, 100%, 93%, 100% and 92.6%, respectively.
Conclusion: The intraoperative evaluation of SLN in endometrial cancer accurately identifies patients with macrometastases. This is the cohort that might benefit the most of a full lymphadenectomy for a higher risk of additional lymph node metastases.
Keywords: Endometrial cancer; ICG; Laparoscopy; Lymphatic metastasis; Pathology; Sentinel lymph node.