Gastrinoma

A type of tumor that secretes gastrin

Gastrinoma

A gastrinoma is a type of neuroendocrine tumor that secretes excessive amounts of the hormone gastrin. This hormone stimulates the stomach to produce acid, leading to peptic ulcers and other gastrointestinal symptoms. Gastrinomas are often associated with a condition known as Zollinger-Ellison syndrome.

Pathophysiology

Gastrinomas arise from the G cells of the duodenum or the pancreas. These tumors are part of a group of neuroendocrine tumors that can secrete various hormones. The overproduction of gastrin by these tumors leads to increased gastric acid secretion, which can cause recurrent and severe peptic ulcers, gastroesophageal reflux disease (GERD), and diarrhea.

Clinical Presentation

Patients with gastrinomas typically present with symptoms related to excessive gastric acid production. These include:

• Recurrent peptic ulcers, often in unusual locations such as the jejunum.
• Abdominal pain.
• Diarrhea, which may be severe and persistent.
• Gastroesophageal reflux disease (GERD).
• Weight loss due to malabsorption and chronic diarrhea.

Diagnosis

The diagnosis of gastrinoma involves several steps:

• Measurement of fasting serum gastrin levels, which are typically elevated.
• Secretin stimulation test, which can help differentiate gastrinomas from other causes of hypergastrinemia.
• Imaging studies such as CT scan, MRI, or somatostatin receptor scintigraphy to localize the tumor.
• Endoscopic ultrasound may be used to identify small tumors in the pancreas or duodenum.

Treatment

The treatment of gastrinoma involves both medical and surgical approaches:

• Medical management: High-dose proton pump inhibitors (PPIs) are used to control gastric acid secretion and manage symptoms.
• Surgical resection: If the tumor is localized and resectable, surgical removal is the preferred treatment.
• Management of metastatic disease: In cases where the tumor has metastasized, treatment may include chemotherapy, targeted therapy, or liver-directed therapies such as embolization.

Prognosis

The prognosis of gastrinoma depends on several factors, including the size and location of the tumor, the presence of metastases, and the patient's overall health. Early detection and treatment can improve outcomes, but metastatic disease may require long-term management.

Related pages

• Zollinger-Ellison syndrome
• Neuroendocrine tumor
• Peptic ulcer disease
• Gastroesophageal reflux disease