Utility and clinical significance of endoscopic ultrasound-guided tissue acquisition for diagnosing lymphadenopathies in biliary tract cancer.

Lymph node sampling with endoscopic ultrasound fine needle aspiration (EUS-FNA) may affect treatment options for biliary tract cancers. Our aim is to clarify its utility and clinical significance and the factors associated with FNA cytology positivity. Seventy-one consecutive patients with biliary tract cancer who underwent EUS-FNA to diagnose lymphadenopathies from April 2012 to July 2021 were enrolled retrospectively. Lymph nodes with a short diameter over 10 mm and/or fluorodeoxyglucose uptake were considered FNA targets. Samples eligible for cytology were attained in 70 patients with no complications. The FNA cytology-positive rate was 54%. In 35 patients with difficulty in obtaining pathological proof from primary tumors, obtaining a pathological diagnosis was successful in 24 patients. Thirteen of 16 FNA cytology-positive patients who were diagnosed with preoperative regional lymph node metastasis received chemotherapy prior to surgery. All seven FNA cytology-positive patients who were diagnosed with distant metastasis received systemic chemotherapy. Multivariate analyses showed a neutrophil-to-lymphocyte ratio over 2.5 (odds ratio (OR) 4.69, p = 0.04), fluorodeoxyglucose uptake (OR 5.34, p = 0.014), and a short diameter over 10.6 mm (OR 6.11, p = 0.018) as factors related to FNA cytology positivity. EUS-FNA of lymphadenopathies in biliary tract cancers may affect clinical biliary tract cancer strategies.