Tissue acquisition for diagnosis of proximal biliary lesions using endoscopic ultrasound-guided fine-needle aspiration.

Objectives: To report the diagnostic yield and safety of endoscopic ultrasound-guided fine-needle aspiration (EUS FNA) for the evaluation of proximal bile duct lesions. Materials and methods: A retrospective analysis of data of the patients, who had undergone EUS for proximal bile duct lesions was done. FNA was performed from either the bile duct mass, enlarged node, or liver lesions. Outcome measures were the diagnostic yield of EUS FNA and adverse events. Results: From April 2011 to August 2018, 147 patients with suspected proximal bile duct malignancy underwent EUS. Mass lesion was seen in 133 (90.47%) patients. FNA was performed in 125 (85.03%) patients. The final diagnosis in patients undergoing EUS FNA was malignancy in 118, benign disease in six, and one patient was lost to follow up. EUS FNA confirmed the diagnosis in 103/118 patients with malignancy (sensitivity 87.28%); was false negative in 15/118 cases with malignancy, and was truly negative in all the six patients with benign disease (specificity 100%). Positive predictive value, negative predictive value, and the accuracy of EUS FNA were 100%, 28.57%, 87.90% respectively. No serious adverse event was reported, five patients had self-limiting pain. Conclusion: EUS FNA is a sensitive tool for the evaluation of proximal bile duct lesions. Low negative predictive value warrants further evaluation in patients with non-malignant findings on cytology.