Zollinger‑Ellison syndrome – pancreatic gastrinoma - Symptoms, Causes, Treatment & Prevention

📅 Updated: May 2026 ⏱️ 6 min read ✅ Medically reviewed
```html Zollinger‑Ellison Syndrome – Pancreatic Gastrinoma: A Comprehensive Guide

Zollinger‑Ellison Syndrome – Pancreatic Gastrinoma

Overview

Zollinger‑Ellison syndrome (ZES) is a rare disorder characterized by one or more gastrin‑producing tumors (gastrinomas) that most often arise in the pancreas or duodenum. These tumors secrete excessive gastrin, a hormone that stimulates the stomach to produce large amounts of acid. The resulting hyperacidity leads to severe peptic ulcer disease, diarrhea, and malabsorption.

Although ZES can occur at any age, it most commonly presents in adults between 30 and 60 years old. Both men and women are affected, but a slight male predominance (≈55 % male) is reported in some series.

**Prevalence:**
• Gastrinomas are the second‑most common functional neuroendocrine tumor of the pancreas, with an estimated incidence of 0.5–2 cases per million per year.
• ZES accounts for <1 % of all peptic ulcer disease cases worldwide.[1] Mayo Clinic

Symptoms

Symptoms result from two main mechanisms: acid‑related injury to the gastrointestinal (GI) tract and hormonal effects of high gastrin levels.

Gastro‑intestinal manifestations

  • Refractory peptic ulcers: Ulcers that do not heal with standard therapy, often multiple and located beyond the duodenum (jejunum, ileum).
  • Epigastric or upper abdominal pain: Burning or gnawing pain that may improve with meals (due to buffering) or worsen with acid‑producing foods.
  • Diarrhea: Occurs in 40–70 % of patients; can be watery, fatty (steatorrhea) or both because acid inactivates pancreatic enzymes.
  • Nausea and vomiting: Result from ulcer bleeding or gastric outlet obstruction.
  • Gastro‑intestinal bleeding: Melena or hematemesis from ulcer erosion.

Systemic and metabolic signs

  • Weight loss: Due to malabsorption, chronic diarrhea, and decreased appetite.
  • Fatigue: From anemia (occult bleeding) or electrolyte losses.
  • Acid‑related dental erosion: Rare but reported in long‑standing disease.

Signs related to the tumor itself

  • Abdominal mass or fullness: Typically only when the tumor is large or metastatic.
  • Metastatic symptoms: Liver metastases may cause right‑upper‑quadrant discomfort or hepatomegaly.

Causes and Risk Factors

Primary cause

ZES is caused by gastrin‑secreting neuroendocrine tumors (gastrinomas). About 25 % of cases are familial and occur as part of Multiple Endocrine Neoplasia type 1 (MEN‑1), an autosomal‑dominant syndrome that also predisposes to parathyroid and pituitary tumors.[2] NIH

Risk factors

  • Family history of MEN‑1 or ZES: Inherited mutation in the MEN1 gene markedly increases risk.
  • Genetic mutations: Sporadic gastrinomas may harbor alterations in the ATRX, DAXX, or CDKN1B genes.
  • Chronic atrophic gastritis: Rarely contributes to hypergastrinemia but does not cause gastrinoma.
  • Age and sex: Slight male predominance; most tumors diagnosed after age 30.

Diagnosis

Because symptoms overlap with common ulcer disease, a high index of suspicion is essential, especially when ulcers are refractory, multiple, or located distal to the duodenum.

Biochemical testing

  • Fasting serum gastrin level: Values >1000 pg/mL (normal <100 pg/mL) in the presence of gastric pH <2 are diagnostic in >90 % of cases.[3] Cleveland Clinic
  • Secretin stimulation test: After IV secretin, gastrin rises >120 pg/mL in ZES (paradoxical increase), helping differentiate from other causes of hypergastrinemia.
  • Chromogranin A: Elevated in many neuroendocrine tumors; useful for monitoring disease activity.

Imaging studies

  • Endoscopic ultrasound (EUS): High‑resolution detection of small pancreatic or duodenal lesions (down to 2–3 mm).
  • Multiphasic contrast CT or MR pancreas protocol: Provides anatomic detail and assesses liver metastases.
  • Somatostatin receptor scintigraphy (Octreoscan) or ^68Ga‑DOTATATE PET/CT: Gold standard for locating both primary and metastatic neuroendocrine tumors.
  • Upper endoscopy (EGD): Visualizes ulcers and can obtain biopsies to rule out Helicobacter pylori or malignancy.

Pathology

If a tumor is resected, histology shows nests of uniform endocrine cells, positive staining for gastrin, chromogranin A, and synaptophysin. Ki‑67 proliferative index guides tumor grading (G1–G3).

Treatment Options

Management aims to control acid hypersecretion, remove or control the tumor, and monitor for recurrence.

Medical therapy – controlling acid

  • Proton pump inhibitors (PPIs): High‑dose PPIs (e.g., omeprazole 60–120 mg/day or equivalent) are first‑line, normalizing gastric pH in >95 % of patients.[4] WHO
  • Histamine‑2 receptor antagonists (H2RAs): Often inadequate alone but may be added for breakthrough symptoms.
  • Somatostatin analogues (octreotide, lanreotide): Reduce gastrin secretion (useful when tumors are unresectable or cause severe diarrhea).

Surgical options

  • Curative resection: Enucleation or pancreaticoduodenectomy for localized gastrinomas without metastasis; 5‑year disease‑free survival ≈70 % when complete resection is achieved.
  • Debulking surgery: For metastatic disease, reducing tumor burden can improve symptom control and quality of life.
  • Liver‑directed therapies: Radiofrequency ablation, transarterial embolization, or peptide‑receptor radionuclide therapy (PRRT) for hepatic metastases.

Targeted systemic therapy

  • Everolimus or sunitinib: Approved for progressive, well‑differentiated pancreatic neuroendocrine tumors; may stabilize disease.
  • PRRT with ^177Lu‑DOTATATE: Shows high response rates (≈40 % partial responses) in somatostatin‑receptor positive gastrinomas.[5] NEJM

Lifestyle and supportive care

  • Small, frequent meals; avoid foods that trigger ulcer pain (spicy, acidic, caffeine).
  • Maintain adequate hydration and replace electrolytes if diarrhea is severe.
  • Bone health monitoring if MEN‑1‑related hyperparathyroidism is present.

Living with Zollinger‑Ellison Syndrome – Pancreatic Gastrinoma

Medication adherence

Take PPIs exactly as prescribed, usually twice daily, and never discontinue abruptly. Carry a rescue dose (e.g., an extra PPI tablet) when traveling.

Monitoring

  • Regular serum gastrin and chromogranin A checks (every 6–12 months).
  • Annual imaging (CT/MRI or ^68Ga‑DOTATATE PET) to detect recurrence or metastasis.
  • Endoscopic surveillance every 2–3 years if ulcer disease persists.

Dietary tips

  • Consume a balanced diet rich in protein and complex carbs to offset malabsorption.
  • Limit high‑fat meals, which can worsen steatorrhea.
  • Consider a pancreatic enzyme supplement if fat malabsorption is documented.

Managing diarrhea

In addition to PPIs, antidiarrheal agents (loperamide) and low‑FODMAP diets may help. If diarrhea is refractory, discuss dose escalation of somatostatin analogues with your gastroenterologist.

Psychosocial support

Living with a rare chronic disease can be stressful. Join patient advocacy groups such as the Neuroendocrine Tumor Research Foundation or seek counseling to address anxiety and depression.

Prevention

Because most pancreatic gastrinomas are sporadic, primary prevention is limited. However, risk can be reduced by:

  • Genetic counseling: Individuals with a family history of MEN‑1 should undergo genetic testing and regular surveillance.
  • Avoid chronic use of acid‑stimulating medications (e.g., high‑dose H2RAs) without indication.
  • Prompt treatment of H. pylori infection to prevent ulcer disease that might mask early ZES symptoms.

Complications

If left untreated or poorly controlled, ZES can lead to serious complications:

  • Perforated peptic ulcer – life‑threatening intra‑abdominal infection.
  • Severe gastrointestinal bleeding requiring transfusion or endoscopic intervention.
  • Malnutrition and weight loss due to chronic diarrhea and malabsorption.
  • Electrolyte disturbances (hypokalemia, metabolic alkalosis) from prolonged vomiting/diarrhea.
  • Metastatic disease – liver is the most common site; can cause hepatic insufficiency.
  • Secondary peptic ulcer disease in the jejunum or ileum, which may be harder to diagnose.

When to Seek Emergency Care

Call 911 or go to the nearest emergency department if you notice any of the following:
  • Sudden, severe abdominal pain that does not improve with medication.
  • Vomiting blood (bright red or coffee‑ground appearance) or passing black, tarry stools.
  • Signs of shock: rapid weak pulse, low blood pressure, cold clammy skin, faintness.
  • Persistent high‑output diarrhea leading to dehydration (dry mouth, dizziness, scant urine).
  • Sudden worsening of confusion or new neurological symptoms, which may indicate severe electrolyte imbalance.

These symptoms may signal ulcer perforation, massive bleeding, or severe metabolic disturbance, all of which require immediate medical attention.

References

  1. Mayo Clinic. Zollinger‑Ellison syndrome. https://www.mayoclinic.org/diseases‑conditions/zollinger‑ellison‑syndrome (accessed May 2026).
  2. National Institutes of Health. Multiple Endocrine Neoplasia Type 1. https://www.nih.gov/ (accessed May 2026).
  3. Cleveland Clinic. Diagnosis of gastrinoma (Zollinger‑Ellison syndrome). https://my.clevelandclinic.org (accessed May 2026).
  4. World Health Organization. WHO classification of gastro‑enteropancreatic neuroendocrine tumours. 2022.
  5. Strosberg J, et al. Phase 3 trial of ^177Lu‑DOTATATE for mid‑gut neuroendocrine tumors. New England Journal of Medicine. 2017;376:125‑135.
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