Source:http://linkedlifedata.com/resource/umls/id/C1332250
NCI: An aggressive neuroendocrine carcinoma arising from the ampulla of Vater and the periampullary region. Morphologically, it is characterized by the presence of small malignant cells, necrosis, and a high mitotic rate. Signs and symptoms include jaundice, abdominal pain, anorexia, nausea, vomiting, and weight loss.