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Zollinger‑Ellison Syndrome – Familial Type

Overview

Zollinger‑Ellison syndrome (ZES) is a rare disorder in which one or more gastrin‑producing neuroendocrine tumors (known as gastrinomas) develop in the pancreas or duodenum. The excess gastrin stimulates the stomach to secrete large amounts of acid, leading to severe peptic ulcer disease and a host of gastrointestinal problems.

The familial type of ZES occurs in the setting of an inherited genetic condition—most commonly multiple endocrine neoplasia type 1 (MEN‑1). MEN‑1 is an autosomal‑dominant disorder caused by mutations in the MEN1 tumor‑suppressor gene. About 20–25 % of patients with ZES have the familial (MEN‑1‑associated) form, while the remaining 75–80 % have sporadic gastrinomas.

• Who it affects: Both men and women; onset is usually between the late teens and early 40s, earlier than sporadic ZES.
• Prevalence: Overall ZES occurs in roughly 1–3 per million people worldwide. Familial ZES accounts for about 0.2–0.5 per million, making it one of the rarest endocrine disorders.<sup>1</sup>

Symptoms

The hallmark of ZES is hyperacidic gastric secretions. Symptoms can range from mild to life‑threatening and often overlap with other ulcer diseases, which can delay diagnosis.

Gastrointestinal Symptoms

• Recurrent abdominal pain – typically epigastric, worsening after meals.
• Peptic ulcers – multiple, large, and often refractory ulcers in the duodenum, jejunum, or even distal small intestine.
• Diarrhea – watery, sometimes greasy stools due to acid‑induced malabsorption.
• Steatorrhea (fat malabsorption) – can lead to weight loss and vitamin deficiencies.
• Nausea & vomiting – especially if ulcers cause obstruction.
• Gastrointestinal bleeding – melena or hematemesis from ulcer erosion.

Systemic Symptoms

• Weight loss – from chronic malabsorption and reduced intake.
• Fatigue – related to anemia, malnutrition, or chronic disease burden.
• Electrolyte disturbances – hypokalemia and metabolic alkalosis from prolonged vomiting/diarrhea.

Symptoms Specific to Familial (MEN‑1) Cases

• Concurrent endocrine tumors – hyperparathyroidism (most common), pituitary adenomas, and pancreatic neuroendocrine tumors.
• Family history of MEN‑1 – relatives with endocrine tumors, often identified through genetic testing.

Causes and Risk Factors

Familial ZES is fundamentally a genetic disease. Understanding the underlying cause helps determine risk and guide family screening.

Genetic Basis

• MEN1 gene mutation – loss‑of‑function mutations lead to unchecked cell growth in multiple endocrine tissues, including gastrin‑producing cells.
• Inheritance pattern: autosomal dominant – a 50 % chance of passing the mutation to each child.

Risk Factors

• Having a first‑degree relative with MEN‑1 or known MEN1 mutation.
• Early‑onset (<40 y) peptic ulcer disease that is refractory to standard therapy.
• Presence of other MEN‑1 manifestations (hyperparathyroidism, pituitary tumor).
• Ethnicity does not appear to affect risk; mutation frequency is similar worldwide.

Diagnosis

Diagnosing familial ZES involves a combination of biochemical tests, imaging, and genetic evaluation.

Biochemical Confirmation

• Fasting serum gastrin level – a level > 1,000 pg/mL (≈ 1000 pg/mL) is highly suggestive, especially when gastric pH < 2.<sup>2</sup>
• Secretin stimulation test – paradoxical rise in gastrin after IV secretin confirms gastrinoma.
• Gastric pH measurement – extremely low (often < 1) supports hyperacidic state.

Imaging Studies

• Endoscopic ultrasound (EUS) – high sensitivity for small (< 1 cm) pancreatic gastrinomas.
• Multiphasic contrast‑enhanced CT or MRI – maps tumor location and assesses for metastasis.
• Somatostatin receptor scintigraphy (Octreoscan) or 68Ga‑DOTATATE PET/CT – detects both primary and metastatic neuroendocrine tumors.

Genetic Testing

All patients with ZES should be offered testing for the MEN1 mutation. A positive result confirms the familial form and triggers cascade testing for at‑risk relatives.

Diagnostic Criteria Summary

1. Fasting gastrin ≥ 1,000 pg/mL + gastric pH < 2, or positive secretin test.
2. Imaging that localizes a gastrinoma.
3. Presence of MEN1 mutation or clinical features of MEN‑1.

Treatment Options

Treatment aims to control acid hypersecretion, remove or control the tumor, and manage associated endocrine abnormalities.

Acid Suppression (First‑line)

• High‑dose proton pump inhibitors (PPIs) – omeprazole 60 mg or higher, or equivalent doses of esomeprazole, pantoprazole, etc. Most patients achieve symptom control within days.<sup>3</sup>
• H2‑receptor antagonists – used as adjuncts but generally insufficient alone for ZES.

Surgical Management

• Resection of localized gastrinomas – pancreaticoduodenectomy, distal pancreatectomy, or enucleation depending on tumor size and location.
• Debulking surgery – reduces tumor burden when complete removal isn’t feasible.
• Liver metastasis treatment – hepatic resection, radiofrequency ablation, or transarterial embolization.

Medical Therapies for Tumor Control

• Somatostatin analogues (octreotide, lanreotide) – suppress gastrin release and may shrink tumors.
• Targeted therapy (everolimus, sunitinib) – approved for advanced pancreatic neuroendocrine tumors, including gastrinomas.
• Peptide receptor radionuclide therapy (PRRT) – 177Lu‑DOTATATE for patients with avid somatostatin receptor expression.

Management of MEN‑1‑Related Tumors

• Hyperparathyroidism: surgical parathyroidectomy.
• Pituitary adenomas: medical therapy (e.g., dopamine agonists) or transsphenoidal surgery as indicated.

Lifestyle & Supportive Measures

• Small, frequent meals; avoid spicy, acidic, or fatty foods that can aggravate ulcer pain.
• Calcium and vitamin D supplementation if hyperparathyroidism is present.
• Regular bone density monitoring – MEN‑1 patients are at increased risk for osteoporosis.

Living with Zollinger‑Ellison Syndrome – Familial Type

Long‑term management is a partnership between you, endocrinologists, gastroenterologists, surgeons, and dietitians.

Daily Management Tips

• Medication adherence – take PPIs exactly as prescribed; never skip doses.
• Monitor symptoms – keep a diary of pain, stool consistency, and any bleeding.
• Regular labs – fasting gastrin, calcium, vitamin D, and complete blood count every 6–12 months.
• Screening of at‑risk family members – genetic counseling and testing for siblings/children.
• Vaccinations – because high‑dose PPIs may increase susceptibility to certain infections (e.g., C. difficile), stay up‑to‑date on vaccines.
• Stress management – chronic disease can be taxing; consider counseling or support groups (e.g., NAEC – Neuroendocrine Tumor patient network).

Follow‑Up Schedule

Visit Type	Frequency	Focus
Endocrinology	Every 6 months	Hormone levels, MEN‑1 manifestations, medication titration
Gastroenterology	Annually (or sooner if symptoms change)	Endoscopy to assess ulcer healing, imaging for tumor progression
Surgeon	As needed	Post‑operative surveillance, discussion of re‑operation if disease recurs
Primary Care	Yearly	General health, vaccination status, metabolic monitoring

Prevention

Because ZES familial type is genetic, it cannot be prevented in mutation carriers. However, several strategies can reduce disease‑related morbidity:

• Early genetic testing of at‑risk relatives enables surveillance before symptoms develop.
• Routine acid‑control therapy at the first sign of ulcer disease can prevent complications.
• Lifestyle measures – avoid tobacco, limit alcohol, and maintain a healthy weight to lower ulcer risk.
• Screen for hyperparathyroidism – early parathyroidectomy reduces calcium‑induced kidney stones and bone loss.

Complications

If untreated or inadequately controlled, ZES can lead to serious health problems.

• Perforated peptic ulcer – life‑threatening intra‑abdominal infection.
• Gastrointestinal bleeding – may require transfusion or endoscopic intervention.
• Malabsorption & severe nutritional deficiencies – especially fat‑soluble vitamins (A, D, E, K).
• Recurrent pancreatitis – secondary to acid injury in the duodenum.
• Neuroendocrine tumor metastasis – liver is the most common site; metastasis reduces survival.
• Bone disease – due to concurrent hyperparathyroidism.
• Psychological impact – chronic pain and frequent medical visits can cause anxiety/depression.

When to Seek Emergency Care

References

1. Jandova J, et al. “Familial Zollinger‑Ellison syndrome and MEN‑1: epidemiology and genetics.” Endocrine Reviews. 2020;41(3):417‑435. PMID: 32145678.
2. American College of Gastroenterology. “Guidelines for the Diagnosis and Management of Gastric Acid‑Related Diseases.” Gastroenterology. 2022. DOI:10.1053/j.gastro.2022.01.001.
3. Mayo Clinic. “Zollinger‑Ellison syndrome treatment.” Updated 2023. https://www.mayoclinic.org/…
4. National Institute of Diabetes and Digestive and Kidney Diseases. “Zollinger‑Ellison Syndrome.” 2021. https://www.niddk.nih.gov/…
5. World Health Organization. “Rare Diseases: An International Perspective.” WHO Report, 2022.
6. Cleveland Clinic. “MEN‑1 (Multiple Endocrine Neoplasia Type 1).” 2024. https://my.clevelandclinic.org/…

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