A comprehensive guide to lymph node staging of cholangiocarcinoma by endoscopic ultrasound

Abstract Accurate lymph node (LN) staging is critical for treatment planning in patients with perihilar cholangiocarcinoma (pCCA) and intrahepatic cholangiocarcinoma (iCCA). Cross-sectional imaging however has limited sensitivity for detecting LN metastases. Recent studies have demonstrated that endoscopic ultrasound (EUS) offers additional value in LN assessment for both pCCA and iCCA. Despite its advantages, reliably identifying the individual LN stations relevant to these malignancies can be challenging and requires detailed knowledge of regional anatomy. This article provides a standardized, systematic guide for identifying all major LN stations associated with pCCA and iCCA using linear EUS, with the aim of improving preoperative staging and optimizing treatment planning.