Which islet cell tumor causes gastric acid hypersecretion resulting in ulcers?

The islet cell tumor responsible for causing gastric acid hypersecretion, which can lead to the development of gastric ulcers, is gastrinoma. Gastrinomas are a type of neuroendocrine tumor that primarily secretes gastrin, a hormone that stimulates gastric acid production by the stomach lining. This overproduction of gastric acid can result in excessive acidity in the gastrointestinal tract, leading to peptic ulcers, particularly in the duodenum.

In contrast, insulinomas primarily produce insulin, resulting in symptoms related to insulin secretion and hypoglycemia, rather than affecting gastric acid secretion. Somatostatinomas secrete somatostatin, which can inhibit various hormones and has different clinical implications unrelated to gastric acid secretion specifically. Non-functioning islet cell tumors do not secrete active hormones, meaning they do not have direct effects on gastric acid production or ulcer formation.

Therefore, gastrinomas are uniquely characterized by their ability to induce hypersecretion of gastric acid and are the primary tumors linked to gastric ulcers.