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Persistently raised PSA after previous negative prostate biopsy — MSRA MCQ

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HardPI-RADSPersistently raised PSA after previous negative prostate biopsyMSRA

A 64-year-old man is reviewed after a persistently raised PSA. He remains fit for radical treatment if clinically significant prostate cancer is diagnosed. A systematic transrectal biopsy 2 years ago was benign. His PSA is 7.4 micrograms/L and MRI-derived prostate volume is 40 mL (PSA density 0.19 ng/mL/mL). Digital rectal examination is benign. Multiparametric MRI shows a 9 mm peripheral-zone abnormality with linear, wedge-shaped mild hypointensity on the ADC map and corresponding mild high signal on high-b-value diffusion-weighted imaging (DWI score 2). There is focal early enhancement at the same site, but no focal T2-weighted mass or extracapsular extension. The overall MRI Likert score is 2. Which PI-RADS v2.1 interpretation and next diagnostic management step is most appropriate?

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Correct answer: A — Classify the lesion as PI-RADS 2 and offer repeat prostate biopsy after shared decision-making

Explanation lettering: C = shown as A · E = shown as B · A = shown as C · B = shown as E

The lesion remains PI-RADS 2. In the peripheral zone, DWI is the dominant sequence. Positive dynamic contrast enhancement is used only to upgrade an equivocal DWI score 3 peripheral-zone lesion to PI-RADS 4; it does not upgrade a DWI score 2 lesion. The linear, wedge-shaped morphology and absence of a focal T2-weighted mass further support low-suspicion appearances. However, PI-RADS and Likert assessment do not alone determine management. This man has a low-risk MRI (Likert 2) but persistent clinical suspicion after a previous negative biopsy: his PSA density is 0.19 ng/mL/mL, exceeding NICE's example threshold of 0.15 ng/mL/mL for strong suspicion. NICE therefore supports offering repeat biopsy, taking account of life expectancy, comorbidity and shared decision-making. A is wrong because DCE positivity does not upgrade DWI 2 to PI-RADS 4. B and E would be appropriate only if overall suspicion were low; his PSA density is high. D incorrectly upgrades the lesion to PI-RADS 3 and applies the MDT pathway for a negative biopsy with Likert 3 or more. A repeat biopsy need not be MRI-targeted when MRI has not identified a suspicious target.

Reference: NICE NG131: Prostate cancer: diagnosis and management — MRI and biopsy; if the MRI or biopsy is negative (2019; checked 16 August 2026) — https://www.nice.org.uk/guidance/ng131/chapter/Recommendations Low cancer yield in PI-RADS 3 upgraded to 4 by dynamic contrast-enhanced MRI: is it time to reconsider scoring categorization? (2023) — https://pubmed.ncbi.nlm.nih.gov/37045981/