​Pathology - Gastrinoma 
Gastrinoma, also known as Zollinger-Ellison Syndrome
The patient is diagnosed with gastrinoma, which is a type of pancreatic tumor that produces and releases gastrin. Gastrin, typically secreted by the G cells in the stomach, activates the parietal cells in the stomach. This leads to an elevation in the proton concentration within the stomach, thereby resulting in an increase in acidity. Gastrin further promotes the growth of parietal cells, leading to an additional rise in the production of acid. The heightened acidity in the gastrointestinal system is not counteracted by the protective mucosal barrier facilitated by prostaglandins, resulting in the formation of ulcers. If the ulcers perforate the vessels, the ulceration might lead to abdominal pain and bleeding. Gastrinomas are predominantly found in the region known as the "gastrinoma triangle," which is defined by the convergence of the hepatic and cystic ducts at the top, the neck of the pancreas, and the intersection of the second and third parts of the duodenum. A gastrinoma can be definitively diagnosed by a secretin stimulation test. Normally, secretin suppresses the production of gastrin. However, in this particular condition, the G cells persist in producing gastrin despite the presence of secretin. Medical therapy involves the use of Proton Pump Inhibitors (PPIs). Excising the gastrinoma cells with surgery, despite its challenging nature, typically leads to a complete cure.