Rare Disease Day 2025: Understanding Gastrinoma and Zollinger-Ellison Syndrome (ZES)

Gastrinoma is a rare neuroendocrine tumor that secretes excess gastrin, leading to Zollinger-Ellison syndrome (ZES). This condition is characterized by severe peptic ulcer disease and chronic diarrhea due to excessive stomach acid production. Gastrinomas typically arise in the duodenum or pancreas and can be sporadic or associated with multiple endocrine neoplasia type 1 (MEN-1).

Key Facts About Gastrinoma & ZES

Diagnosis:

• Requires fasting serum gastrin level measurement (99% sensitivity).
• Gastrin levels >1000 pg/mL with gastric pH <2 confirm ZES.
• Secretin stimulation test helps distinguish ZES from other hypergastrinemic conditions.
• Endoscopic ultrasound and Gallium-68 PET scans are highly effective for tumor localization.

Treatment:

• Proton pump inhibitors (PPIs) are the primary therapy for managing symptoms.
• Surgery is recommended for localized sporadic ZES.
• Advanced cases may require somatostatin analogs, chemotherapy, or liver-directed therapies.
• Metastatic disease does not always exclude surgical intervention.

Gastrinoma and ZES remain challenging to diagnose and manage, requiring early detection and a multidisciplinary approach. This Rare Disease Day, we raise awareness to improve outcomes for those affected by this rare but serious condition.

References:

• J Neuroendocrinol. 2023 Apr;35(4):e13267. doi: 10.1111/jne.13267. Epub 2023 Apr 11.
• World J Gastroenterol. 2021 Sep 21;27(35):5890-5907. doi: 10.3748/wjg.v27.i35.5890.