A doctor diagnoses ZES by
A doctor may suspect ZES if diarrhea accompanies peptic ulcer symptoms or if treatment for peptic ulcers fails. Most peptic ulcers are caused by bacteria called Helicobacter pylori (H. pylori) or the use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen. Peptic ulcers in the absence of H. pylori infection or NSAIDs usage or severe peptic ulcers that bleed or cause perforation of the duodenum are possible indicators of ZES. A MEN1 diagnosis in the patient or the patient’s family or the presence of MEN1 signs and symptoms strongly suggests ZES.
Multiple ulcers in the duodenum—seen during upper gastrointestinal (GI) endoscopy—may cause a doctor to suspect ZES. Upper GI endoscopy is used to see inside the upper GI tract. During the procedure, an endoscope—a thin, flexible, lighted tube with a small camera on the tip—is inserted through the mouth, esophagus, and stomach and into the duodenum. The endoscope sends images taken inside the upper GI tract to a video monitor where they can be viewed. Upper GI endoscopy, however, rarely reveals gastrinomas, which grow in tissue layers beneath the visible surface.
A procedure called somatostatin receptor scintigraphy (SRS)—sometimes called OctreoScan—is used to find gastrinomas in the duodenum, pancreas, and other parts of the body. SRS uses a radioactive compound called a radiotracer that, when injected into the bloodstream, selectively labels tumor cells. The labeled cells light up when scanned with a device called a gamma camera.
Other imaging procedures used to find gastrinomas include the following: