Zollinger Ellison Syndrome or ZE Syndrome is a disease caused by increased production of Gastrin. The syndrome is termed as state of ¬†Hypergastrinemia due to cancer of Gastrin producing cells.Gastrin is normally secreted by G cells present in stomach on response to distention of stomach, Vagal stimulation or decreased acid production [Negative feedback loop]. Somatostain and Secretin inhibits the release of Gastrin thereby decreasing the acid production in the stomach.
Read regulation of acid production in stomach.
The location of cancerous G Cells secreting large amount of Gastrin in ZE syndrome is usually found in duodenum ¬†and pancreas instead of stomach. While almost 20 percent of them is associated with MEN type 1. Multiple Endocrine Neoplasia which includes parathyroid, pituitary and pancreatic tumors.
Symptoms of Zollinger Ellison Syndrome
Ulcer Disease: 95 percent of ZES cases present with a peptic ulcer disease, while only 1 % of ulcer disease has ZES or gastrinoma. The clue towards an Ulcer disease with an underlying Zollinger Ellison syndrome are as follows:
- Recurrent ulcers after PUD therapy
- Multiple ulcers in the distal part of duodenum
- Ulcers greater than 1 cm in size
- Ulcers not resolving even after H.pylori thrapy
Presence of Hypercalcemia along with ulcer disease [ suggestive of MEN-1 with Hyperparathyrodism]
Associated Diarrhea: along with steatorrhea [Fatty sticky stools] : As increase levels of acid inactivates lipase enzyme which breakdowns fat.
Diagnosing ZE Syndrome
If the clinical assessment of a patient present with recurrent ulcer disease is suggestive of a Gastrinoma or Zollinger Ellison Syndrome, the diagnosis id made by “Secretin Stimulation Test”. The idea behind this test is to measure Gastrin Level after giving a loading dose of secretin.
Point to remember, is that only the random quantitative analysis of Gastrin [increased level] is not specific to ZES. Gastrin level can be high due to PPIs patient has been taking for recurrent ulcer disease. while other causes of increased gastrin levels are:
- Pernicious Anemia
- Chronic Gastritis
- Renal Failure
Secretin Simulation Test
A rise in Gastrin level after injection of secretin is conformation of diagnosis of Zollinger Ellison Syndrome. Normally secretin should suppress Gastrin release.
Once the diagnosis is made, the next step to find out of the disease is localized or metastatic.
Metastatic disease can be found out by somatostatin-receptor scintoigraphy. The single most sensitive test is Endoscopic ultrasound. USG, MRI and CT scan are good tests, if positive are enough to prove the presence of the disease but if negative does not exclude the disease.
Treatment of ZE Syndrome
Localized non metastatic lesions are surgically removed while the metastatic disease is treated by long term administration of PPIs simply to block acid production.