False detection and the value of combined tracer mapping in endometrial cancer: a dual case presentation.

This case report demonstrates two contrasting clinical cases of patients with early-stage endometrial cancer undergoing sentinel lymph node (SLN) mapping. In the first case, a 68-year-old patient with a body mass index (BMI) of 38 underwent SLN mapping using indocyanine green (ICG) alone. Although fluorescence-guided dissection revealed nodes appearing "ICG-positive," histopathological evaluation confirmed the absence of lymphatic tissue in the removed specimens-indicating the presence of so-called "empty nodes." This highlights the limitations of relying solely on optical fluorescence, especially in patients with high BMI or altered lymphatic architecture. In contrast, the second case, involving a 65-year-old patient with a BMI of 40, demonstrates the effectiveness of using a combined technique with ICG and technetium-99m (Tc99m). The synergy between real-time fluorescence visualization and gamma probe detection enabled precise SLN identification and confirmed the presence of true lymphatic tissue histologically. This dual case report underscores the limitations of ICG-only SLN mapping and and illustrates the potential added value of technetium-99m in improving the accuracy of lymphatic staging, warranting further validation.