Zollinger-Ellison syndrome

Zollinger-Ellison syndrome is a rare cause of peptic ulcer disease. It is characterized by multiple peptic ulcerations in the stomach, duodenum and even jejunum. It is caused by neuroendocrine tumors that produce gastrin, called gastrinomas, and they are often located in the pancreas, duodenum or the lymph nodes of the abdomen. Increased gastrin means increased stomach acid.