Simultaneous gallbladder and bile duct cancers: revisiting the pathological possibilities.

The pathogenesis of gallbladder cancer presenting synchronously with malignancy of the bile duct has not been clearly understood. The possible causes for the simultaneous presence of these tumors could be due to local spread, metastases, de novo multifocal origin, or as part of a field change in the extrahepatic biliary apparatus. In this article, we discuss the cases of four patients with simultaneous gallbladder and bile duct malignancies and analyze their individual pathologies to provide an explanation into the mechanisms that may play a role in such conditions.