A 35-year-old man with burning epigastric pain after meals and a pancreatic mass has immunohistochemistry showing antibodies against a hormone. Which hormone is overproduced by this tumor?

A 35-year-old man with burning epigastric pain after meals and a pancreatic mass has immunohistochemistry showing antibodies against a hormone. Which hormone is overproduced by this tumor?

• A. Gastrin
• B. Secretin
• C. Cholecystokinin
• D. Ghrelin

Answer: (B)

This presentation points to a gastrinoma causing Zollinger-Ellison syndrome. A pancreatic neuroendocrine tumor can overproduce gastrin, leading to excessive gastric acid secretion. The resulting high acid burden causes burning epigastric pain after meals and peptic ulcers, explaining the clinic. Immunohistochemistry showing antibodies against a hormone indicates the tumor is producing that hormone, so gastrin is the hormone being secreted in excess. Secretin is produced by S cells in the duodenum and normally stimulates bicarbonate release; it has a paradoxical relationship with gastrin in gastrinomas (secretin can provoke a rise in gastrin during testing), but it is not the hormone produced by the tumor. Cholecystokinin and ghrelin have different sources and effects and don’t explain this clinical picture.

This presentation points to a gastrinoma causing Zollinger-Ellison syndrome. A pancreatic neuroendocrine tumor can overproduce gastrin, leading to excessive gastric acid secretion. The resulting high acid burden causes burning epigastric pain after meals and peptic ulcers, explaining the clinic. Immunohistochemistry showing antibodies against a hormone indicates the tumor is producing that hormone, so gastrin is the hormone being secreted in excess.

Secretin is produced by S cells in the duodenum and normally stimulates bicarbonate release; it has a paradoxical relationship with gastrin in gastrinomas (secretin can provoke a rise in gastrin during testing), but it is not the hormone produced by the tumor. Cholecystokinin and ghrelin have different sources and effects and don’t explain this clinical picture.