Question

Which is the most common functioning pancreatic endocrine neoplasm?

• A. Insulinoma
• B. Gastrinoma
• C. VIPoma
• D. Glucagonoma

Hint:

Think of the beta-cell tumour that causes Whipple's triad.

Answer 1

The Correct Option is A

Anchor on the clinical syndrome and frequency. Of the functioning islet-cell tumours, the beta-cell insulinoma dominates, making up roughly $70$ to $80\%$, with gastrinoma a distant second at about $20$ to $25\%$, and VIPoma and glucagonoma being rare. Insulinoma announces itself with Whipple's triad: neuroglycopenic symptoms, documented low plasma glucose, and prompt relief after glucose, usually from a small, benign, solitary pancreatic lesion. Gastrinoma instead causes refractory peptic ulcers (Zollinger-Ellison), VIPoma gives the WDHA watery diarrhoea syndrome, and glucagonoma produces necrolytic migratory erythema with diabetes, all far less common. So the single most common functioning pancreatic endocrine neoplasm is the insulinoma.