The precise origin of Zollinger-Ellison syndrome remains unknown. However, the syndrome generally unfolds in a consistent sequence. It commences with the formation of one or more tumors within the pancreas or a specific section of the small intestine known as the duodenum, which is adjacent to the stomach. Occasionally, these tumors may develop in other sites, such as nearby lymph nodes.
The pancreas, situated behind and below the stomach, performs multiple functions, including the production of digestive enzymes and hormones like insulin, which regulates blood sugar levels. The duodenum is where pancreatic, liver, and gallbladder juices combine for digestion, a crucial process.
The tumors associated with Zollinger-Ellison syndrome consist of cells that excessively secrete the hormone gastrin, earning them the moniker “gastrinomas.” Elevated gastrin levels prompt excessive stomach acid production, leading to peptic ulcers and potentially diarrhea.
Aside from the heightened acid output, these tumors often possess cancerous attributes. While their growth tends to be gradual, the cancer can metastasize, usually to nearby lymph nodes or the liver.
Link to MEN 1
Zollinger-Ellison syndrome can be attributed to an inherited disorder known as multiple endocrine neoplasia, type 1 (MEN 1). Individuals with MEN 1 experience the presence of tumors in the parathyroid glands, and in some cases, tumors may also form in their pituitary glands.
Approximately a quarter of individuals with gastrinomas are diagnosed with MEN 1. This inherited condition may also give rise to tumors within the pancreas and various other organs.