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Calcium oxalate nephrolithiasis with suspected primary hyperparathyroidism — MSRA MCQ

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HardNephrolithiasisCalcium oxalate nephrolithiasis with suspected primary hyperparathyroidismMSRA

A 44-year-old man is reviewed by his GP 3 weeks after passing his first CT-confirmed 6 mm ureteric stone. Stone analysis shows calcium oxalate. He is now asymptomatic, with normal renal function and no family history of hypercalcaemia. As part of follow-up, his albumin-adjusted serum calcium is 2.64 mmol/L. A repeat albumin-adjusted serum calcium measurement 2 weeks later is 2.67 mmol/L. What is the most appropriate next investigation plan?

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Correct answer: E — Arrange a random parathyroid hormone measurement with concurrent albumin-adjusted serum calcium

This patient has had a calcium-containing renal stone and has persistent albumin-adjusted hypercalcaemia: both measurements are at least 2.6 mmol/L. NICE recommends measuring PTH when albumin-adjusted calcium is at least 2.6 mmol/L on 2 separate occasions. The PTH should be measured from a random sample with concurrent albumin-adjusted calcium. This establishes the appropriate biochemical sequence before decisions about specialist referral or localisation imaging. A 24-hour urinary calcium collection may have a role later in specialist assessment, including differentiation from other causes of PTH-dependent hypercalcaemia, but it should not replace initial PTH testing. Ionised calcium is not recommended for investigating suspected primary hyperparathyroidism. Parathyroid ultrasound and sestamibi scanning are localisation investigations for operative planning, not diagnostic tests. Endocrinology advice is appropriate after the PTH result: NICE advises specialist input where PTH is above the midpoint of the reference range with suspected primary hyperparathyroidism, or where calcium remains raised despite a PTH below the midpoint. The renal stone is clinically important because confirmed primary hyperparathyroidism with end-organ disease warrants consideration of parathyroid surgery.

Reference: NICE NG118: Renal and ureteric stones: assessment and management, metabolic testing (2019; current NICE guidance checked August 2026) — https://www.nice.org.uk/guidance/ng118/chapter/Recommendations NICE NG132: Hyperparathyroidism (primary): diagnosis, assessment and initial management, diagnostic testing in primary care (2019; current NICE guidance checked August 2026) — https://www.nice.org.uk/guidance/ng132/chapter/Recommendations