gastrinoma

Last reviewed 07/2021

The Zollinger-Ellison syndrome describes the association of:

• gastrin-producing tumours
• gastric hypersecretion
• severe peptic ulcer disease

Usually, the tumour is situated in the pancreas but may arise in the upper small intestine or gastric antrum. 60% of the tumours are malignant. 10% are multiple

Patients with the Zollinger-Ellison syndrome may develop diarrhoea and malabsorption due to inhibition of pancreatic lipase by the excessive gastric acid. This syndrome occurs in about 0.1% of patients with duodenal ulcer disease.

Gastrinomas may occurs as part of a multiple endocrine neoplasia syndrome and so screening for pituitary adenomas, parathyroid tumours and other pancreatic tumours may be indicated

• approximately 20–25% of gastrinoma patients have MEN-I syndrome (1)

Diagnosis and investigation of gatrinomas:

• high fasting plasma gastrin
• high gastric acid secretion
• diminished response to pentagastrin
• demonstrable pancreatic or gastrointestinal tumour - by CT or venous sampling for gastrin
• more than 90% of gastrinomas have somatostatin receptors, and somatostatin receptor scintigraphy has been reported to be a especially sensitive method to image gastrinomas

Management:

• management is directed by a specialist
• most patients are managed with proton pump inhibitors
• octreotide can also control acid hypersecretion in patients with Zollinger-Ellison syndrome - this treatment modality has a favourable outcome on the patients' prognosis and survival (1)
• total gastrectomy and parietal cell vagotomy are only seldom necessary
• surgical resection of the primary tumour(s) may improve prognosis and even result in a complete cure (1)
  • note also that there is a general consensus that curative surgery should also be aimed for in metastatic disease, including metastatic disease ‘localized’ to the liver (1)
• systemic chemotherapy is indicated in patients with metastatic disease
• liver transplantation may be considered in patients with no extrahepatic metastases

Notes:

• in diagnosing gastrinoma, the measurement of basal and maximal gastric acid output is mandatory to distinguish it from secondary hypergastrinaemia
• at the time of diagnosis of a gastrinoma, 60–80% have metastasized to regional lymph nodes or to the liver.

Reference:

1. de Herder WW and Lamberts SWJ. Best Practice & Research Clinical Endocrinology & Metabolism 2004; Volume 18(4): 477-495.