A benign or malignant neoplasm involving the ampulla of Vater. The disease is MONDO_0000921 (ampulla of vater neoplasm). Also known as: ampulla of Vater tumor, ampulla of Vater tumour, hepatopancreatic ampulla neoplasm, hepatopancreatic ampulla neoplasm (disease), hepatopancreatic ampulla tumor, hepatopancreatic ampulla tumour, neoplasm of ampulla of Vater, neoplasm of hepatopancreatic ampulla.