Biliary cytology: A diagnostic tree for adenocarcinoma based on a cohort of 135 patients with endoscopic retrograde cholangiopancreatography for stenosis of the extrahepatic bile duct.

A diagnostic tree of malignancy based on 4 criteria, together with a multidisciplinary approach, allows the diagnosis of adenocarcinoma with a specificity of 100% and a sensitivity of 88% or 72% depending on the presence of a single malignant cell or the presence of 3 combined criteria (a 3D cluster, anisonucleosis, and an N:C ratio > 0.5). It comes with a learning atlas useful for cytopathologist training and accuracy in this uncommon cytology.