Benign anatomical mistakes: "ampulla of Vater" and "papilla of Vater".

The anatomy of the ampullary termination of the bile and pancreatic ducts is complex; appropriate terminology for this area is confusing and inaccurate. We examine the terms "ampulla of Vater" and "papilla of Vater" for anatomical and historical correctness. The term "ampulla" refers to a dilated part of a duct or other channel. Thus, this word is topographically correct to describe the dilatation at the confluence of the bile and main pancreatic ducts; historically, however, there is considerable reason to believe that its first description was by Santorini rather than Vater. The eponymous term "papilla of Vater" is also incorrect historically. The use of eponyms is firmly entrenched in the medical literature, but some are so problematic that they should be discarded. The eponymous terms for both the ampulla and the papilla should be replaced with the terms "hepatopancreatic ampulla" (or "biliaropancreatic ampulla") and "major [or "greater"] duodenal papilla," respectively.