A thiy-year-old male presents to the Emergency Depament with symptoms of epigastric pain radiating to back that wakes him up at night and is relieved by consuming food. He gives a history of similar pain in the past which was diagnosed as perforated duodenal ulcer and treated with omental patch surgery on two occasions. Pain before and after surgery has been controlled with proton pump inhibitors and analgesics. The likely diagnosis on this occasion is

**Core Concept**
The patient's symptoms of epigastric pain radiating to the back, relieved by food intake, and a history of recurrent duodenal ulcers, suggest a diagnosis related to peptic ulcer disease (PUD). The pathophysiology involves gastric acid secretion, mucosal defense, and potential Helicobacter pylori infection.

**Why the Correct Answer is Right**
The patient's symptoms, along with his history of recurrent duodenal ulcers, point towards a diagnosis of **Zollinger-Ellison syndrome** (ZES). ZES is characterized by excessive gastric acid secretion due to a gastrin-producing tumor (gastrinoma) leading to recurrent peptic ulcers. The symptoms are relieved by food intake due to the buffering effect of food on gastric acid. The patient's previous treatment with proton pump inhibitors (PPIs) and analgesics controlled the symptoms but did not address the underlying cause.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because **gastric cancer** typically presents with weight loss, early satiety, and a palpable abdominal mass, which are not mentioned in the patient's history.

**Option B:** This option is incorrect because **acute pancreatitis** typically presents with severe abdominal pain radiating to the back, but this pain is not relieved by eating and is usually accompanied by other symptoms like nausea, vomiting, and elevated lipase levels.

**Option C:** This option is incorrect because **cholecystitis** typically presents with right upper quadrant pain, fever, and leukocytosis, which are not mentioned in the patient's history.

**Clinical Pearl / High-Yield Fact**
Recurrent peptic ulcers, particularly in a patient with a history of perforation, should raise the suspicion of Zollinger-Ellison syndrome, especially if the symptoms are not adequately controlled with standard PPI therapy.

**Correct Answer: D. Zollinger-Ellison syndrome**

✓ Correct Answer: A. Duodenal ulcer