A gastrinoma is a neuroendocrine tumor that produces excessive levels of the hormone gastrin, which stimulates the stomach to secrete acid and enzymes, causing peptic ulcers. Gastrinomas are usually located in the pancreas or duodenum (the first segment of the small intestine).
Gastrinomas arise from cells in the pancreas that produce the hormone gastrin.
Symptoms are similar to those caused by peptic ulcers, including abdominal pain and bleeding from the stomach or intestines.
Diagnosis includes blood and imaging tests.
Treatment includes medications to reduce acid in the stomach and sometimes surgery and chemotherapy.
The survival rate is high if the tumor is completely removed.
Gastrinomas are a type of pancreatic endocrine tumor. About half of gastrinomas are cancerous. Gastrinomas usually are small and grow slowly.
The excess gastrin secreted by a gastrinoma causes the stomach to produce far too much acid. This overproduction of acid can result in a condition called Zollinger-Ellison syndrome. The person can develop peptic ulcers or have symptoms of a peptic ulcer (such as abdominal pain or bleeding from the stomach or duodenum [the first part of the small intestine]) even if an ulcer has not formed yet. Severe complications of Zollinger-Ellison syndrome can be life threatening, including severe blood loss or rupture (bursting open) or obstruction of a part of the digestive tract..
Sometimes a gastrinoma occurs as part of multiple endocrine neoplasia, a hereditary disorder in which tumors arise from the cells of various endocrine glands, such as the insulin-producing cells of the pancreas.
Symptoms of Gastrinoma
Symptoms of gastrinoma are the same as for other causes of peptic ulcers, including stomach pain and sometimes blood passed in the stool. Diarrhea is also a common symptom.
If severe complications occur, a person may have heavy bleeding passing with the stool or have vomiting with blood present. Severe blood loss may result in lightheadedness or fainting. A rupture of the digestive tract causes severe abdominal pain. Obstruction causes severe constipation (no stool is passed), abdominal pain, and vomiting.
Diagnosis of Gastrinoma
Blood tests
Imaging tests
A doctor suspects a gastrinoma when a person has frequent peptic ulcers or several peptic ulcers that do not respond to the usual ulcer treatments. Blood tests to detect abnormally high levels of gastrin are the most reliable diagnostic tests.
Once blood tests diagnose gastrinoma, doctors try to locate the tumor using several imaging techniques, such as computed tomography (CT) of the abdomen, scintigraphy (a type of radionuclide scanning), endoscopic ultrasound, positron emission tomography (PET), and arteriography (an x-ray taken after a radiopaque dye is injected into an artery). These tumors may be difficult to find, however, because usually they are small.
Treatment of Gastrinoma
Medications to reduce levels of stomach acid
Sometimes surgical removal
Sometimes chemotherapy
High doses of proton pump inhibitors, which are acid-reducing medications (see table Medications Used to Treat Stomach Acid
If there is only one tumor and the person does not have a condition called multiple endocrine neoplasia, doctors usually do surgery to remove the gastrinoma. About 20% of people with a gastrinoma can be cured by surgery.
If the tumor is cancerous and has spread to other parts of the body (metastasized), chemotherapy is given. This may help reduce symptoms by reducing the number of tumor cells and the levels of gastrin in the blood.
Prognosis for Gastrinoma
If the tumor is completely surgically removed, people have a greater than 90% chance of surviving 5 to 10 years. If the tumor is not completely removed, people have a 43% chance of surviving 5 years and a 25% chance of surviving 10 years.
