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Zollinger‑Ellison Syndrome‑Related Peptic Ulcer Disease

Overview

Zollinger‑Ellison syndrome (ZES) is a rare neuroendocrine tumor disorder in which one or more gastrin‑secreting tumors (gastrinomas) develop, most often in the duodenum or pancreas. The excess gastrin stimulates the stomach’s parietal cells to produce large amounts of gastric acid, leading to severe, recurrent peptic ulcer disease (PUD) that often occurs far downstream from the stomach (duodenum, jejunum) and may be refractory to standard ulcer therapy.

• Who it affects: Adults 30‑60 years old; slight male predominance (≈55 % male). About 20‑25 % of patients have a hereditary form called multiple endocrine neoplasia type 1 (MEN‑1).
• Prevalence: Approximately 1–3 cases per million people worldwide; roughly 500‑1 000 new diagnoses in the United States each year [1].

Symptoms

Symptoms result from high gastric acid, ulcer formation, and, occasionally, from the tumor itself.

Gastro‑intestinal

• Abdominal pain: Burning or gnawing pain that may improve with food (duodenal ulcer pattern) but can become constant as ulcers perforate.
• Diarrhea or steatorrhea: Acid inactivates pancreatic enzymes and damages the mucosa, leading to malabsorption.
• Vomiting: May contain blood (hematemesis) if ulcer erodes a vessel.
• Weight loss: From malabsorption, chronic pain, and reduced intake.

Systemic

• Frequent heartburn/reflux: Due to overwhelming acid production.
• Fatigue & anemia: Chronic blood loss from occult bleeding.
• Recurrent ulcers: Ulcers that fail to heal despite proton‑pump inhibitor (PPI) therapy.

Signs of Tumor Presence

• Palpable abdominal mass (rare).
• Gallium‑68 DOTATATE PET avid lesions (detected on imaging).

Causes and Risk Factors

Primary cause

ZES is caused by gastrin‑producing neuroendocrine tumors (gastrinomas). About 90 % arise in the duodenum, 5‑10 % in the pancreas, and the remainder in lymph nodes or ectopic sites.

Risk factors

• Multiple endocrine neoplasia type 1 (MEN‑1): Autosomal‑dominant syndrome (mutation of the MEN1 gene) that predisposes to pancreatic neuroendocrine tumors, hyperparathyroidism, and pituitary adenomas.
• Familial gastrinoma syndrome: Rare inherited gastrinoma without other MEN‑1 features.
• Age 30‑60 years: Most sporadic gastrinomas are diagnosed in this window.
• Smoking: May increase risk of neuroendocrine tumor development.
• Chronic proton‑pump inhibitor use (rarely): Long‑term acid suppression can lead to hypergastrinemia, but not to gastrinoma; however, it can mask symptoms and delay diagnosis.

Diagnosis

Diagnosing ZES requires confirming hypergastrinemia, demonstrating acid hypersecretion, and localizing the gastrinoma.

Step‑wise approach

1. Fasting serum gastrin level: Levels > 1,000 pg/mL are highly suggestive; levels 200‑1,000 pg/mL require further testing.
2. Secretin stimulation test: In ZES, gastrin paradoxically rises > 120 pg/mL after IV secretin (0.4 U/kg). This test differentiates gastrinoma from other causes of hypergastrinemia (e.g., atrophic gastritis, PPI use).
3. Gastric acid measurement: Gastric pH < 2 after overnight fast confirms acid hypersecretion.
4. Imaging for tumor localization:
   • Multiphasic contrast CT or MRI of the abdomen.
   • Endoscopic ultrasound (EUS) – highly sensitive for small duodenal lesions.
   • Somatostatin receptor imaging (Ga‑68 DOTATATE PET/CT) – gold standard for neuroendocrine tumor detection and staging.
5. Endoscopy: Upper GI endoscopy identifies ulcer location, size, and presence of bleeding.

It is essential to stop PPIs ≥ 7 days before gastrin testing, as they can artificially elevate gastrin levels.

Treatment Options

Medical Management – Controlling Acid Hypersecretion

• High‑dose PPIs: Omeprazole 60‑120 mg/day or esomeprazole 40‑80 mg/day are first‑line; they heal ulcers in > 90 % of patients [2].
• Potassium‑competitive acid blockers (PCABs):** e.g., vonoprazan (approved in Japan, under investigation in U.S.). May be useful in refractory cases.
• H2‑receptor antagonists: Usually insufficient alone but can be added for breakthrough symptoms.

Surgical Management – Removing the Gastrinoma

Curative surgery is the only option to eliminate the source of excess gastrin.

• Pancreaticoduodenectomy (Whipple procedure): For pancreatic head tumors.
• Enucleation or segmental duodenal resection: For small, isolated duodenal gastrinomas.
• Liver metastasis resection or ablation: If disease is limited to the liver.
• Somatostatin analogues (octreotide, lanreotide): Reduce gastrin secretion and may shrink tumors; indicated when surgery is not curative or disease is metastatic.

Adjunct Therapies

• Chemo‑embolization or targeted therapy (e.g., everolimus, sunitinib): For progressive metastatic neuroendocrine tumors.
• Peptide receptor radionuclide therapy (PRRT): ^177Lu‑DOTATATE for somatostatin‑receptor‑positive disease.

Lifestyle & Supportive Measures

• Avoid NSAIDs, aspirin, and alcohol – they aggravate ulcer formation.
• Eat small, frequent meals; limit caffeine and carbonated drinks.
• Maintain adequate hydration and replace fat‑soluble vitamins if malabsorption is present.

Living with Zollinger‑Ellison Syndrome‑Related Peptic Ulcer Disease

Medication adherence

High‑dose PPIs must be taken exactly as prescribed. Missing doses often leads to rapid recurrence of symptoms.

Monitoring

• Serum gastrin and fasting gastric pH every 6‑12 months (or sooner if symptoms change).
• Annual endoscopy to assess ulcer healing and screen for new lesions.
• Imaging (CT/MRI or DOTATATE PET) every 1‑2 years for tumor surveillance, especially in MEN‑1 patients.

Nutrition

Because high acid can inactivate pancreatic enzymes, a low‑fat, high‑protein diet with medium‑chain triglycerides can improve absorption. A registered dietitian experienced with malabsorption can tailor a plan.

Psychosocial support

Chronic disease and the possibility of metastatic cancer can cause anxiety. Referral to counseling, support groups (e.g., NET patient societies), and patient‑education resources is recommended.

When to contact your doctor

• New or worsening abdominal pain.
• Black/tarry stools or vomiting blood.
• Unexplained weight loss > 5 % of body weight in a month.
• Persistent diarrhea (> 3 weeks) or signs of malnutrition.

Prevention

Because ZES is driven by a tumor, primary prevention is limited. However, early detection and risk reduction for ulcer complications are possible.

• Screen high‑risk groups: Individuals with MEN‑1 or a family history of gastrinoma should have periodic fasting gastrin testing.
• Avoid ulcer‑aggravating agents: NSAIDs, aspirin, and excessive alcohol.
• Prompt evaluation of persistent ulcer symptoms: Early endoscopy and gastrin measurement can catch ZES before complications develop.

Complications

• Perforated ulcer: Free air in the abdomen, requiring emergent surgery.
• Bleeding ulcer: May cause anemia or hemorrhagic shock.
• Gastro‑intestinal obstruction: From scarring or tumor mass effect.
• Metastatic disease: Liver, lymph nodes, or bone metastases occur in 25‑50 % of sporadic gastrinomas at diagnosis.
• Malabsorption & osteoporosis: Chronic acid damage impairs nutrient absorption (especially calcium, iron, vitamin B12).
• Refractory ulcer disease: Persistent pain, decreased quality of life, and need for repeated hospitalizations.

When to Seek Emergency Care

Call 911 or go to the nearest emergency department if you experience any of the following:

• Sudden, severe abdominal pain that wakes you from sleep.
• Vomiting blood (bright red) or material that looks like coffee grounds.
• Black, tarry stools (melena) indicating upper GI bleeding.
• Signs of shock: rapid heartbeat, fainting, dizziness, cold clammy skin, or confusion.
• High fever (> 101 °F / 38.3 °C) with abdominal pain – possible perforation with infection.
• Sudden inability to pass gas or stool, accompanied by swelling and severe pain – possible obstruction.

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References (accessed 2024):

1. National Institute of Diabetes and Digestive and Kidney Diseases. Zollinger‑Ellison Syndrome. NIH, 2023.
2. Mayo Clinic. Peptic ulcer disease: Diagnosis & treatment. 2022.
3. American College of Gastroenterology. ACG Clinical Guideline: Management of Gastric Acid Hypersecretion, 2021.
4. World Health Organization. Neuroendocrine Tumors: WHO classification, 2022.
5. Cleveland Clinic. Multiple Endocrine Neoplasia Type 1 (MEN‑1). 2023.

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