Gastrinoma

Abstract

Gastrinomas are functional neuroendocrine tumours, characterized by autonomous release of gastrin by the tumour cells, which results in symptoms not only due to the tumour growth per se, but also due to gastric acid hypersecretion. Gastrinomas can either be sporadic or can be associated with multiple endocrine neoplasia type 1 (MEN-1) syndrome in 25% of cases. The duodenum (especially the first and the second part) is the most common location for both sporadic and MEN-1 associated gastrinomas. Most of the symptoms in patients with gastrinomas include peptic ulcers resistant to treatment, erosive oesophagitis, and chronic diarrhoea. Fasting serum gastrin levels of >10-fold the upper normal limit in the presence of gastric p H<2 or basal acid output (BAO)>15 mmol/h confirm the clinical suspicion, of a gastrinoma. Precise localization of primary tumour as well as metastatic deposits can be achieved through the new molecular imaging studies (68Ga-DOTA PET) in combination with good quality cross-sectional imaging studies and endoscopic ultrasound. Once the diagnosis is established, it is important to control gastric acid hypersecretion and prevent its complications, by using high-doses proton pump inhibitors. The aim of surgery in patients with sporadic gastrinomas is curative resection, in order to decrease the risk of development of distant metastases, as well as to completely control the hormonal symptoms. The benefit of surgery in gastrinomas associated with MEN-1 syndrome is controversial. All patients with advanced and inoperable disease should have systemic antitumour treatment (somatostatin analogues, molecular targeted agents, chemotherapy, peptide receptor radionuclide therapy) in order to prolong the survival rates.