A 40-year-old female complains of frequent diarrhea and abdominal pain between meals. Endoscopy reveals a duodenal ulcer distal to the duodenal bulb. CT scan of the abdomen demonstrates a pancreatic mass, and subsequent tissue biopsy of the pancreas reveals a malignant islet cell tumor. Which of the following hormones is likely to be markedly elevated in this patient:
4.Vasoactive intestinal peptide
The patient is suffering from Zollinger-Ellison (ZE) syndrome due to a pancreatic gastrinoma. Excess gastrin secretion leads to excess gastric acid production in the stomach, often resulting in peptic ulcer disease.
Atypical ulcers, such as a duodenal ulcer distal to the duodenal bulb (the first part of the duodenum), multiple ulcers, and ulcers refractory to therapy are all suggestive of ZE syndrome. Diarrhea due to acidic inactivation of pancreatic enzymes may also be present in patients with ZE syndrome. Serum gastrin levels are dramatically increased in patients with ZE syndrome.
Macaron reviews endocrine-secreting pancreatic tumors. Examples include, insulinoma, glucagonoma, gastrinoma (ZE syndrome), VIPoma, somatostatinoma and others. Hormones are produced by specific tumor cell types and cause dramatic clinical presentations.
Oberg reviews the pathophysiology and clinical presentation of pancreatic endocrine tumors, including gastrinomas. Ectopic gastrin secretion from pancreatic endocrine tumors or duodenal tumors (gastrinomas) cause ZE syndrome. Excessive acid secretion leads to peptic ulcers and gastric esophagus reflux disease (GERD).
Illustration A shows an endoscopy image of multiple small ulcers in the distal duodenum in a patient with Zollinger–Ellison syndrome.