A gastrinoma is a relatively rare type of tumor found most commonly in the first part of the small intestine, or duodenum, and less frequently in the pancreas. Patients may have several small tumors or a single large tumor. These types of tumors secrete large amounts of a hormone called gastrin, which stimulates the increased production of gastric acid in the stomach; this is commonly known as Zollinger-Ellison syndrome. The majority of gastrinomas become cancerous, at which point they often spread to surrounding tissues and organs such as the liver.
People with gastrinomas typically have extensive ulcers in the stomach and small intestine, due to the large secretions of gastric acid triggered by the gastrin. This often leads to abdominal pain. They also often have severe diarrhea stemming from the overproduction of acid, and may experience nausea and vomiting as well. Though treating the gastrinoma, which is the source of the symptoms, is the main goal, proton pump inhibitors, or PPIs, may also be used to control the gastric acid being produced.
Some patients with gastrinomas have them present as part of a larger issue known as multiple endocrine neoplasia, or MEN. Those with MEN are afflicted with a variety of syndromes that cause tumors in several different endocrine system areas. Gastrinomas are frequently associated with MEN type 1, where tumors are also found in the pituitary and parathyroid glands.
To diagnose a gastrinoma, the doctor will typically want to understand a patient's history first. Gastrinomas often present with recurrent peptic ulcer disease or Zollinger-Ellison syndrome, so patients with those issues will be more likely to have them. A blood test will then be done to analyze the patient's level of gastrin to help confirm a diagnosis. Imaging techniques such as CT scans, PET scans, or areteriography can then be used to confirm the location of the tumor or tumors.
Treatment for a gastrinoma typically involves surgery. Due to the likelihood of the tumors becoming cancerous, it is usually necessary to have them removed. Different surgical procedures may be necessary if there are multiple tumors located in different places. If the tumors are small, it may be possible to remove only the tumors from the pancreas, duodenum, or occasionally from other surrounding tissues. Larger tumors may necessitate the removal of a portion of the pancreas as well.