ZollingerEllisonsyndrom

Zollinger-Ellison syndrome is a rare disorder caused by gastrin-secreting neuroendocrine tumors called gastrinomas. These tumors drive excessive gastric acid production, leading to peptic ulcers and related complications. Most gastrinomas arise in the pancreas or duodenum, and many are malignant. The condition is sometimes associated with MEN1.

Pathophysiology: Gastrinomas secrete gastrin independent of normal regulation, causing marked hypergastrinemia and acid hypersecretion. The secretin stimulation test can reveal a paradoxical rise in gastrin and helps confirm the diagnosis.

Clinical features include severe, recurrent peptic ulcers, often in unusual locations, with possible bleeding or perforation. Diarrhea and steatorrhea are common due to inactivation of pancreatic enzymes by excess acid.

Diagnosis relies on suspected refractory ulcers or ulcers not explained by NSAIDs. Fasting serum gastrin levels and gastric pH assessment are first steps; very high gastrin levels (>1000 pg/mL) with low pH support the diagnosis. Imaging includes CT, MRI, endoscopic ultrasound, and functional studies such as somatostatin receptor scintigraphy or Ga-68 DOTATATE PET to localize tumors and detect metastases. Screening for MEN1 is recommended.

Management emphasizes acid control and tumor-directed therapy. High-dose proton pump inhibitors heal ulcers and control symptoms. Surgical resection is considered for localized disease; metastatic disease may be managed with debulking, somatostatin analogs (octreotide), and other systemic therapies. In MEN1, management includes surveillance for other endocrine tumors.

Prognosis varies with tumor size, grade, and metastasis. Localized gastrinomas have better outcomes than metastatic disease. Advances in imaging and therapies have improved diagnosis and symptom control, but Zollinger-Ellison syndrome typically requires long-term follow-up.