Diagnostic value of inguinal ultrasound for predicting histological lymph node status in vulvar cancer

As part of the pretherapeutic diagnostic workup for vulvar cancer, the inguinal lymph node status should be assessed. The diagnostic value of structured inguinal sonography for predicting the histological lymph node status in patients with vulvar cancer should be determined.

All patients diagnosed with vulvar cancer and scheduled for surgical removal of inguinal lymph nodes were included in the prospective unicentric cohort study from March 2023 to May 2025. Preoperatively, inguinal ultrasound was performed according to the Vulvar International Tumor Analysis (VITA) protocol. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined. These were compared with the retrospectively collected results of an inguinal ultrasound examination, which was not performed according to the VITA protocol, in patients who had undergone surgery between January 2016 and February 2023.

Lymph node sonography performed according to the VITA protocol, followed by inguinofemoral surgery, was conducted in 74 groins. Lymph node metastases could be identified with a sensitivity of 64.3%, a specificity of 78.3%, a PPV of 40.9%, and an NPV of 90.4%. In 92 groin surgeries in patients without application of the VITA protocol, a sensitivity of 56.3%, a specificity of 89.5%, a PPV of 52.9%, and an NPV of 90.7% were determined, which did not differ significantly from the VITA cohort (p > 0.05).

Overall, even after the introduction of a structured examination protocol specifically designed for vulvar cancer, inguinofemoral sonography did not demonstrate higher accuracy in determining the histological lymph node status.