MONDO_0004117 (ampulla of vater small cell neuroendocrine carcinoma) is 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. Also known as: ampulla of Vater small cell NEC, ampulla of Vater small cell carcinoma, ampulla of Vater small cell neuroendocrine carcinoma, ampullary small cell carcinoma, hepatopancreatic ampulla small cell carcinoma, small cell neuroendocrine carcinoma of the ampullary region.