Long QT Syndrome and Duodenal Ampullary Adenoma: A New Association.

KCNQ1 gene mutation has a well-known association with long QT syndrome (LQTS). However, recent studies suggest that it may be implicated in intestinal neoplasia. We present a 27-year-old Hispanic man with a known history of LQTS secondary to KCNQ1 mutation, who presented with painless jaundice. Endoscopic retrograde pancreatic cholangiography revealed a prominent ampulla, with histology consistent with ampullary adenoma with high-grade dysplasia. Further endoscopic studies did not suggest familial adenomatous polyposis. To date, this is the index case of duodenal ampullary adenoma in the setting of KCNQ1 mutation.