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Asymptomatic non-obstructing renal calculus — MSRA MCQ

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HardNephrolithiasisAsymptomatic non-obstructing renal calculusMSRA

A 46-year-old man is reviewed in urology after an 8 mm non-obstructing lower-pole renal calculus is identified incidentally on CT performed during assessment of uncomplicated diverticulitis. He has never had renal colic, urinary infection or stone passage. Renal function is normal, urinalysis is negative for blood and infection, and there is no hydronephrosis. He has no solitary kidney or relevant anatomical abnormality. After discussion, he wishes to avoid a procedure unless there is a clear benefit from immediate treatment. What is the most appropriate management plan?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: D — Agree watchful waiting after informed discussion of risks and benefits

This is an asymptomatic, non-obstructing renal stone. NICE advises that watchful waiting should be considered for asymptomatic renal stones under 5 mm and may also be considered for stones larger than 5 mm when the person agrees after an informed discussion of risks and benefits. Therefore, an 8 mm stone does not itself mandate intervention. Option E is attractive because NICE recommends SWL as the usual first active treatment for renal stones smaller than 10 mm. However, that treatment table applies when active intervention has been selected; it does not override the separate recommendation permitting observation for asymptomatic stones. Option A would be reasonable if SWL were contraindicated, unsuitable anatomically, or unsuccessful, but none applies here. Option B is disproportionate for an uncomplicated 8 mm renal stone; PCNL is generally reserved after less invasive options fail or are unsuitable. Option C is inappropriate because medical expulsive therapy is considered for distal ureteric stones, not a non-obstructing stone remaining in the renal calyx. The key distinctions are renal rather than ureteric location, absence of symptoms or obstruction, and shared decision-making for a stone larger than 5 mm.

Reference: NICE NG118: Renal and ureteric stones: assessment and management — Recommendations (Published 08 January 2019; current NICE recommendations checked August 2026) — https://www.nice.org.uk/guidance/ng118/chapter/Recommendations NICE NG118: Renal and ureteric stones: assessment and management — Surgical treatment and medical expulsive therapy (Published 08 January 2019; current NICE recommendations checked August 2026) — https://www.nice.org.uk/guidance/ng118/chapter/Recommendations