Paraneoplastic syndromes, including Cushing syndrome due to ectopic ACTH, acromegaly due to ectopic growth hormone–releasing factor, and Zollinger-Ellison syndrome due to
[msdmanuals.com]
Depending on which substances are being released by the tumors, the person will have the various symptoms of carcinoid syndrome, insulinoma syndrome, Zollinger Ellison syndrome
[nlc.hu]
[…] pain (often secondary to fibrosis) Gastric carcinoids Type 1 associated with chronic atrophic gastritis – absent acid secretion and hypergastrinemia Type 2 associated with Zollinger-Ellison
[arupconsult.com]