View source for Zollinger-Ellison syndrome

==Introduction==
Zollinger-Ellison syndrome (ZES) is a rare disorder characterized by the development of [[Gastrinoma|gastrin-secreting tumors]] (gastrinomas) in the [[Pancreas|pancreas]] and [[Duodenum|duodenum]]. These gastrinomas lead to an overproduction of [[Gastrin|gastrin]], a hormone that stimulates the production of stomach acid. The excessive acid, in turn, leads to peptic ulcers, diarrhea, and other gastrointestinal symptoms.

[[Image:Detail-72781.jpg|thumb|center|A microscopic view of a gastrin-secreting tumor, also known as a gastrinoma.|class=only_on_mobile]]
[[Image:Detail-72782.jpg|thumb|center|A microscopic view of a gastrin-secreting tumor, also known as a gastrinoma.|class=only_on_desktop]]

==Etiology==
The exact cause of Zollinger-Ellison syndrome is unknown. However, approximately 25-30% of cases are associated with [[Multiple endocrine neoplasia type 1|MEN1]], a hereditary condition that causes tumors in the endocrine glands. In these cases, the gastrinomas are often multiple and are located in both the pancreas and duodenum.

==Clinical Features==
The clinical features of Zollinger-Ellison syndrome are primarily related to the hypersecretion of gastric acid. The most common symptoms include abdominal pain, diarrhea, and [[Gastroesophageal reflux disease|GERD]]. The abdominal pain is often severe and may be mistaken for other conditions such as [[Gallstone|gallstones]] or [[Appendicitis|appendicitis]]. Diarrhea is typically persistent and may lead to weight loss. GERD, characterized by heartburn and regurgitation, is also common due to the excessive acid production.

==Diagnosis==
The diagnosis of Zollinger-Ellison syndrome is based on clinical features, laboratory tests, and imaging studies. The key laboratory test is the measurement of fasting serum gastrin levels. In ZES, these levels are typically markedly elevated. However, a definitive diagnosis requires a positive secretin stimulation test, in which gastrin levels fail to suppress following the administration of [[Secretin|secretin]]. Imaging studies, including [[Computed tomography|CT]], [[Magnetic resonance imaging|MRI]], and [[Endoscopic ultrasound|EUS]], are used to locate the gastrinomas.

==Treatment==
The primary treatment for Zollinger-Ellison syndrome is the reduction of gastric acid secretion. This is typically achieved with [[Proton-pump inhibitor|proton pump inhibitors]] (PPIs), which are highly effective in controlling symptoms and healing peptic ulcers. In cases where the gastrinomas can be localized and are not widespread, surgical removal may be considered. However, surgery is not curative in most cases due to the presence of multiple tumors or metastasis.

==Prognosis==
The prognosis of Zollinger-Ellison syndrome varies depending on the extent of disease and the presence of metastasis. With appropriate treatment, the symptoms of ZES can be effectively managed, and the quality of life can be significantly improved. However, the overall survival rate is lower in patients with metastatic disease.

==See Also==
* [[Peptic ulcer disease]]
* [[Gastrointestinal hormones]]
* [[Endocrine tumors]]

[[Category:Gastrointestinal disorders]]
[[Category:Endocrine diseases]]
[[Category:Rare diseases]]