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Zollinger‑Ellison Syndrome in Children

Overview

Zollinger‑Ellison syndrome (ZES) is a rare condition in which one or more tumors (called gastrinomas) form in the pancreas or the duodenum. These tumors secrete large amounts of the hormone gastrin, which overstimulates the stomach’s acid‑producing cells. The resulting hyperacidic environment leads to recurrent peptic ulcers, diarrhea, and malabsorption.

While ZES most commonly presents in adults (average age ≈ 45 years), it can occur in children and adolescents. Pediatric ZES accounts for < 1 % of all gastrin‑producing tumors, with an estimated incidence of 0.5–1 case per million children per year.<sup>1</sup> Both genders are affected equally.

Most pediatric cases are linked to a hereditary condition called **multiple endocrine neoplasia type 1 (MEN 1)**, but sporadic (non‑inherited) gastrinomas also occur.

Symptoms

The hallmark of ZES is excessive gastric acid that damages the lining of the stomach and duodenum. Children may present with any combination of the following signs and symptoms:

Gastro‑intestinal (GI) symptoms

• Recurrent peptic ulcers – often multiple, difficult to heal, and may be located beyond the duodenum (e.g., jejunum, ileum).
• Abdominal pain – crampy, epigastric, sometimes radiating to the back; pain may worsen after meals.
• Chronic diarrhea – watery, fatty (steatorrhea) due to acid inactivation of pancreatic enzymes.
• Vomiting – may be non‑bloody; occasional nausea.
• Gastro‑esophageal reflux disease (GERD) – heartburn refractory to standard treatment.
• Weight loss or failure to thrive – despite normal or increased appetite.

Systemic symptoms

• Fatigue, anemia (iron‑deficiency) from chronic bleeding.
• Electrolyte disturbances (low potassium, magnesium) secondary to diarrhea.
• Bone pain or fractures (rare) if associated with MEN 1‑related hyperparathyroidism.

Signs that may suggest MEN 1

• Hypercalcemia or kidney stones.
• Skin lesions (facial angiofibromas, collagenomas).
• Family history of endocrine tumors.

Causes and Risk Factors

ZES results from gastrinoma cells that secrete gastrin autonomously. The main categories are:

1. Sporadic gastrinomas

• Develop without an identifiable genetic cause; account for ~60 % of pediatric cases.
• Most are solitary and located in the duodenum (≈ 70 %) or pancreas (≈ 25 %).

2. MEN 1‑associated gastrinomas

• MEN 1 is an autosomal‑dominant disorder caused by mutations in the MEN1 tumor‑suppressor gene.
• Children with MEN 1 have a 30‑40 % lifetime risk of developing gastrinomas.
• Other MEN 1 manifestations (parathyroid hyperplasia, pituitary adenomas) often appear before, during, or after ZES diagnosis.

Risk Factors

• Positive family history of MEN 1 or other endocrine tumors.
• Known MEN1 gene mutation.
• Rarely, exposure to high‑dose radiation (e.g., for other cancers) has been linked to pancreatic neuroendocrine tumors, but the connection to pediatric ZES is not well established.

Diagnosis

Because the symptoms overlap with common pediatric GI disorders, a high index of suspicion is required. Diagnosis combines clinical assessment, laboratory testing, and imaging.

1. Laboratory evaluation

• Fasting serum gastrin level – a value > 1000 pg/mL (or > 10‑fold the upper limit) is highly suggestive, especially when gastric pH is low (< 2).<sup>2</sup>
• Secretin stimulation test – after intravenous secretin, gastrin rises > 120 pg/mL in ZES (pathognomonic).
• Basic metabolic panel to assess electrolytes, calcium, and renal function.
• Complete blood count to look for anemia.
• If MEN 1 is suspected: serum calcium, parathyroid hormone, prolactin, and pituitary hormone panel.

2. Imaging studies

• Endoscopic ultrasound (EUS) – highly sensitive for small duodenal or pancreatic lesions.
• Contrast‑enhanced CT or MRI of the abdomen – first‑line cross‑sectional imaging to locate tumors and assess metastasis.
• Somatostatin receptor scintigraphy (Octreoscan) or ^68Ga‑DOTATATE PET/CT – detects neuroendocrine tumors that express somatostatin receptors; useful when CT/MRI are negative.
• Upper endoscopy (EGD) – documents ulcer disease, biopsies rule out Helicobacter pylori, and can occasionally visualize the tumor if it protrudes into the lumen.

3. Genetic testing

If a family history or other MEN 1 features are present, genetic counseling and testing for MEN1 mutations are recommended. Identifying a mutation guides surveillance for other endocrine tumors.

Treatment Options

Therapy aims to (1) control acid hypersecretion, (2) eradicate or control the gastrinoma, and (3) address any MEN 1‑related disease.

1. Acid‑suppression therapy

• High‑dose proton pump inhibitors (PPIs) – omeprazole, esomeprazole, or pantoprazole. Doses are 3–5 times the adult standard (e.g., omeprazole 20–40 mg twice daily for a 30‑kg child). PPIs are the mainstay; they heal ulcers and improve diarrhea.
• H2‑receptor antagonists (cimetidine, ranitidine) may be added initially, but PPIs are superior for ZES.

2. Surgical management

• Curative resection is preferred when the tumor is solitary, <5 cm, and without metastasis.
• Procedures include:
  • Local excision or duodenotomy for duodenal gastrinomas.
  • Pancreaticoduodenectomy (Whipple) for larger pancreatic lesions.
• In children, minimally invasive (laparoscopic) techniques are increasingly used, reducing recovery time.
• Even after complete resection, long‑term PPI therapy is usually continued because microscopic disease may persist.

3. Medical therapy for unresectable or metastatic disease

• Somatostatin analogues (octreotide LAR, lanreotide) – inhibit gastrin release and can stabilize tumor growth.
• Targeted therapy – everolimus (mTOR inhibitor) or sunitinib (tyrosine‑kinase inhibitor) are approved for progressive pancreatic neuroendocrine tumors in adults; pediatric use is off‑label and reserved for refractory disease under specialist supervision.
• Peptide receptor radionuclide therapy (PRRT) – ^177Lu‑DOTATATE for tumors with high somatostatin‑receptor expression; limited pediatric data but promising in select centers.
• Systemic chemotherapy (streptozocin‑based regimens) is rarely needed in children.

4. Management of MEN 1 components

• Hyperparathyroidism – surgical parathyroidectomy if hypercalcemia is symptomatic.
• Pituitary adenomas – dopamine agonists, surgery, or radiotherapy per endocrinology guidelines.

5. Lifestyle and supportive measures

• Small, frequent meals low in fat to reduce gastric emptying time.
• Avoidance of NSAIDs, aspirin, and cigarettes (if applicable) because they aggravate ulcer formation.
• Supplementation of fat‑soluble vitamins (A, D, E, K) if chronic steatorrhea is present.
• Regular growth monitoring and nutrition assessment by a pediatric dietitian.

Living with Zollinger‑Ellison Syndrome in Children

Managing ZES is a team effort involving pediatric gastroenterology, surgery, endocrinology, nutrition, and psychology. Below are practical tips for families:

• Medication adherence – set alarms for PPI doses; use a pill organizer.
• Follow‑up schedule – routine endoscopy every 1–2 years to assess ulcer healing; imaging (CT/MRI) annually if the tumor was not completely removed.
• School accommodations – provide a written plan for medication administration and emergency contacts; discuss potential need for bathroom breaks.
• Psychosocial support – chronic illness can affect self‑esteem. Counseling or support groups for children with rare endocrine disorders are beneficial.
• Family screening – if MEN 1 is diagnosed, test siblings and parents; early detection of other endocrine tumors improves outcomes.
• Travel tips – carry a “medical passport” with diagnosis, medication list, and emergency contacts; keep PPIs in carry‑on luggage.

Prevention

Because ZES is largely driven by genetic mutations, primary prevention is limited. However, the following steps can reduce secondary complications:

• Prompt treatment of H. pylori infection, which can exacerbate ulcer disease.
• Avoid chronic use of acid‑irritating medications (NSAIDs, steroids).
• Maintain a balanced diet that prevents severe malnutrition and supports a healthy gut microbiome.
• For families with known MEN 1 mutations, early genetic counseling and routine surveillance (annual calcium, gastrin, and imaging studies) can detect tumors when they are most treatable.

Complications

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

• Refractory or perforated peptic ulcers – may cause intra‑abdominal bleeding or peritonitis.
• Gastrointestinal bleeding – chronic occult blood loss leading to iron‑deficiency anemia.
• Severe malabsorption – chronic diarrhea and steatorrhea cause weight loss, growth failure, and deficiencies of vitamins A, D, E, K.
• Gastrointestinal strictures or obstruction – from repeated ulcer healing and scarring.
• Metastatic gastrinoma – spreads to regional lymph nodes, liver, or lungs; associated with a 5‑year survival of ~50 % without aggressive therapy.
• MEN 1‑related sequelae – hyperparathyroidism (kidney stones, osteoporosis), pituitary adenomas (visual field loss, hormonal imbalances).

When to Seek Emergency Care

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References:

1. American College of Gastroenterology. “Zollinger‑Ellison Syndrome.” ACG Clinical Guideline, 2022.
2. Mayo Clinic. “Zollinger-Ellison syndrome – Diagnosis.” Updated 2023.
3. National Institute of Diabetes and Digestive & Kidney Diseases (NIDDK). “Zollinger‑Ellison Syndrome.” 2021.
4. Cleveland Clinic. “Gastrinoma (Zollinger-Ellison Syndrome) – Pediatric Considerations.” 2024.
5. World Health Organization. “Classification of Neuroendocrine Tumors.” WHO Tumor Classification, 5th edition, 2023.

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