Gastrinoma is a type of neuroendocrine tumor that primarily affects the pancreas or duodenum (the first part of the small intestine). These tumors produce excessive amounts of gastrin, a hormone that stimulates the stomach to produce acid. This overproduction of gastrin leads to increased stomach acid secretion, resulting in a condition known as Zollinger-Ellison syndrome (ZES). ZES causes recurrent peptic ulcers in the stomach and duodenum, as well as gastroesophageal reflux disease (GERD).
Peptic ulcers: These are ulcers that form in the lining of the stomach or duodenum. They can cause abdominal pain, bloating, nausea, and vomiting.
Gastroesophageal reflux disease (GERD): This condition causes stomach acid to flow back into the esophagus, leading to heartburn, chest pain, and difficulty swallowing.
Diarrhea: Chronic diarrhea can occur due to increased acid secretion and irritation of the intestines.
Abdominal pain: This pain may be persistent and can range from mild to severe.
Weight loss: Unintentional weight loss may occur due to decreased appetite and malabsorption of nutrients.
The treatment of gastrinoma typically involves a combination of medical therapy, surgical intervention, and management of complications such as ulcers and reflux.
Medications: Proton pump inhibitors (PPIs) are commonly prescribed to reduce stomach acid production and alleviate symptoms of ulcers and reflux.
Surgery: Surgical removal of the tumor (gastrinoma) and affected parts of the pancreas or duodenum may be recommended, especially if the tumor is localized and has not spread to other organs.
Embolization: For tumors that cannot be surgically removed, embolization may be performed to block the blood supply to the tumor, reducing its size and symptoms.
Chemotherapy: In cases where the tumor has spread to other organs, chemotherapy may be used to shrink the tumor and alleviate symptoms.
Lifestyle modifications: Dietary changes, such as avoiding spicy foods, alcohol, and caffeine, can help reduce symptoms of ulcers and reflux. Additionally, quitting smoking and managing stress can also be beneficial.
Blood tests: Elevated levels of gastrin in the blood can indicate gastrinoma. Other blood tests may be performed to assess for complications such as anemia or electrolyte imbalances.
Endoscopy: A flexible tube with a camera is inserted through the mouth to visualize the stomach and duodenum. This allows the doctor to identify ulcers and take tissue samples (biopsies) for examination.
Imaging tests: CT scans, MRI scans, or somatostatin receptor scintigraphy (OctreoScan) can help locate the tumor and determine its size and spread.
Secretin stimulation test: This test involves injecting a hormone called secretin and measuring gastrin levels before and after. In patients with gastrinoma, gastrin levels will remain elevated even after secretin injection.
Endoscopic ultrasound (EUS): This procedure combines endoscopy and ultrasound to obtain detailed images of the pancreas and surrounding structures, aiding in the detection of tumors.
Genetic testing: In some cases, genetic testing may be recommended to check for inherited conditions associated with gastrinomas, such as multiple endocrine neoplasia type 1 (MEN1) syndrome.