skip to main content

Suspected clinically localised prostate cancer — MSRA MCQ

Instant feedback + full explanation. One question, done properly.

ModeratePI-RADSSuspected clinically localised prostate cancerMSRA

A 58-year-old man is investigated on the suspected prostate cancer pathway. He would be suitable for radical treatment if clinically significant prostate cancer is diagnosed. His PSA is 5.8 micrograms/L, MRI-derived prostate volume is 72 mL (PSA density 0.08 ng/mL/mL), and digital rectal examination is benign. Multiparametric MRI identifies a 13 mm anterior transition-zone lesion. It is heterogeneous and moderately T2-hypointense with obscured margins (T2-weighted score 3). It is markedly hypointense on the ADC map and markedly hyperintense on high-b-value diffusion-weighted imaging, without extracapsular extension (DWI score 4). Which reporting interpretation and immediate diagnostic management is most appropriate?

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

Reveal the answer and explanation

Correct answer: D — Classify the lesion as PI-RADS 3 and offer an MRI-influenced prostate biopsy.

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

The transition zone is assessed primarily using T2-weighted imaging. This lesion has a T2-weighted score of 3: heterogeneous, moderately hypointense signal with obscured margins. Although there is marked restricted diffusion, the lesion is 13 mm and therefore has a DWI score of 4 rather than 5. In PI-RADS v2.1, a transition-zone lesion with T2 score 3 and DWI score 4 remains PI-RADS 3; it is upgraded to PI-RADS 4 only when the DWI score is 5. NICE recommends MRI-influenced prostate biopsy for an MRI Likert score of 3 or more. The low PSA density does not override this recommendation where the MRI finding is equivocal/suspicious at Likert 3. Therefore, MRI-influenced biopsy is appropriate. A is incorrect because the MRI appearances are not PI-RADS 2. B is attractive because of the low PSA density, but NICE does not recommend deferring biopsy solely on that basis when the MRI score is 3 or more. D incorrectly upgrades marked diffusion restriction to PI-RADS 4 without meeting the DWI-5 criterion. E incorrectly applies the PI-RADS 5 size threshold; there is neither a lesion of at least 15 mm nor extracapsular extension.

Reference: NICE NG131: Prostate cancer: diagnosis and management, recommendations 1.2.2-1.2.3 (2019; last reviewed August 2025) — https://www.nice.org.uk/guidance/ng131/chapter/recommendations PI-RADS v2.1: What has changed and how to report (2021) — https://pubmed.ncbi.nlm.nih.gov/34230862/