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 63-year-old man is investigated on the suspected prostate cancer pathway. He is fit for radical treatment if clinically significant prostate cancer is diagnosed. His PSA is 6.4 micrograms/L, MRI-derived prostate volume is 55 mL and digital rectal examination is benign. Multiparametric MRI identifies a 9 mm anterior transition-zone nodule with an incomplete capsule, classified as T2-weighted score 2 (an atypical benign prostatic hyperplasia nodule). It shows focal marked hypointensity on ADC and marked hyperintensity on high-b-value diffusion-weighted imaging, giving a DWI score of 4. Dynamic contrast-enhanced imaging shows focal early enhancement. There is no extracapsular extension. The reporting radiologist assigns an overall Likert score of 3. Which combined PI-RADS v2.1 classification and next diagnostic step is most appropriate?

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

Reveal the answer and explanation

Correct answer: A — Classify the lesion as PI-RADS 3 and perform an MRI-influenced prostate biopsy

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

This is a PI-RADS v2.1 category 3 lesion, followed by MRI-influenced prostate biopsy. In the transition zone, T2-weighted imaging is the dominant sequence. However, PI-RADS v2.1 introduced a specific exception for an atypical BPH nodule: a transition-zone lesion with T2 score 2 because of an incomplete or absent capsule is upgraded from PI-RADS 2 to PI-RADS 3 when there is marked diffusion restriction (DWI score 4 or 5). Positive dynamic contrast enhancement does not further upgrade this transition-zone lesion to PI-RADS 4. The locally assigned Likert score is 3, which is independently decisive in the UK diagnostic pathway: NICE recommends MRI-influenced biopsy for Likert scores of 3 or more. The low PSA density does not override that recommendation in a biopsy-naive man with a Likert 3 MRI. A incorrectly ignores the v2.1 upgrade pathway and would lead to inappropriate surveillance. B has an inappropriate PI-RADS classification, although biopsy is appropriate because the Likert score is 3. D is tempting because of marked diffusion restriction and enhancement, but a T2 score 2 atypical BPH nodule is upgraded by one category only. E requires features supporting the highest-suspicion category, which are absent.

Reference: Prostate cancer: diagnosis and management (NG131), recommendations 1.2.2-1.2.3 (2019) — https://www.nice.org.uk/guidance/ng131/chapter/recommendations Prospective PI-RADS v2.1 Atypical Benign Prostatic Hyperplasia Nodules With Marked Restricted Diffusion (2020) — https://pubmed.ncbi.nlm.nih.gov/32876473/