|Micrograph of a neuroendocrine tumour of the stomach. H&E stain.|
A gastrinoma is a tumor in the pancreas or duodenum that secretes excess of gastrin leading to ulceration in the duodenum, stomach and the small intestine. There is hypersecretion of HCl acid into the duodenum, which causes the ulcers. Excessive HCl acid production also causes hyperperistalsis, and inhibits the activity of lipase, causing severe diarrhea.
It is usually found in the duodenum, although it may arise in the stomach or pancreas. Those occurring in the pancreas have a greater potential for malignancy. Most gastrinomas are found in the gastrinoma triangle; this is bound by the junction of cystic and common bile ducts, junction of the second and third parts of the duodenum, and the junction of the neck and body of the pancreas.
Signs and symptoms
Gastrinoma causes the following symptoms:[medical citation needed]
- Ulcers of the duodenum, stomach, and small intestine.
- Severe diarrhea.
- Generalized cancer symptoms.
- Fasting serum gastrin
- In case of moderate hypergastrinemia, a secretin stimulation test can help in the diagnosis
- Localization by somatostatin scintigraphy