What are malignant duodenal tumors?

Adenocarcinoma: 67% periampullary Risk factors are Crohn disease, ulcerative colitis, polyposis syndromes, villous adenomas, hereditary nonpolyposis colon cancer Also include lymphoma; GIST (10–30% malignant). Symptoms and signs Abdominal pain, GI or biliary obstruction, GI bleeding (hematochezia or melena), weight loss; lymphoma: fever, night sweats, palpable abdominal mass. Endoscopy and biopsy are usually diagnostic