stomach itself. About 4% of gastric ulcers are caused by a malignant tumor, so multiple biopsies are needed to exclude cancer. Duodenal ulcers are generally benign . Contents 1 Classification 2 Signs and symptoms 2.1 Complications 3 Cause 3.1 A predisposing Cause? 3.2 Another predisposing factor 3.3 Stress 4 Diagnosis 4.1