A 45-year-old man has multiple refractory duodenal ulcers and a fasting gastrin of 1200 pg/mL with a positive secretin stimulation test. Before planning operative localisation and excision of a gastrinoma, which additional evaluation is mandatory?
- A Serum prolactin and visual field assessment
- B Serum cortisol and overnight dexamethasone suppression testing
- C Serum calcium and intact parathyroid hormone levels ✓
- D Serum calcitonin and carcinoembryonic antigen levels
Correct answer: C. Serum calcium and intact parathyroid hormone levels
Explanation
About a quarter of patients with Zollinger-Ellison syndrome have MEN1, in which hyperparathyroidism is the usual first manifestation. Unrecognised hyperparathyroidism drives hypergastrinaemia further, and the surgical strategy changes because parathyroidectomy is performed first and duodenotomy-based gastrinoma excision may be avoided. Cortisol, prolactin and calcitonin relate to other MEN components or unrelated tumours and do not gate gastrinoma surgery.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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