Cytomorphologic characteristics of next-generation sequencing-positive bile duct brushing specimens.

Introduction: Cytology of bile duct brushings (BDBs) is a specific, but insensitive, test for malignancy. Next-generation sequencing (NGS) of BDBs has recently been shown to improve sensitivity. We analyzed the cytologic features of NGS-positive (NGS) and NGS-negative (NGS) BDBs and correlated the morphology with the presence of mutations.