Gastrinoma
A gastrinoma is a tumor derived from G cells in the duodenum, pancreas or less commonly stomach, that secretes the peptide hormone gastrin. 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 frequently the source of the gastrin in Zollinger-Ellison syndrome.
A gastrinoma in the pancreas has 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:
- Hypergastrinemia
- Ulcers of the duodenum, stomach, and small intestine.
- Severe diarrhea.
- Generalized cancer symptoms.
Diagnosis
- Fasting serum gastrin
- In case of moderate hypergastrinemia, a secretin stimulation test can help in the diagnosis
- Localization by somatostatin scintigraphy
Treatment
Treatment can involve surgery or proton pump inhibitors.
