Case Study #5: A PI-RADS 3 Lesion

Chad Ellimoottil

Sep 29

2 min read

This case is hypothetical — written for teaching, to help you understand how I think through decisions about elevated PSA. It is not based on any real patient.

History

Dave is a 66-year-old man referred by his primary care doctor for a rising PSA. He reports some nighttime urination but no weak stream or urgency. His prostate exam was normal. He is otherwise healthy and takes a daily statin.

PSA trend

2023 — 4.1 ng/mL 2024 — 4.8 ng/mL 2025 — 5.4 ng/mL October 2026 — 5.9 ng/mL Rising steadily — mildly elevated and climbing.

Secondary testing

Prostate MRI: PI-RADS 3 lesion (10 mm, transition zone) — equivocal, cannot reliably distinguish benign from significant cancer
Prostate volume by MRI: 45 cc — PSA density: 0.13 ng/mL/cc

Previous biopsy

Dave has never had a prostate biopsy.

Family history

Dave's father was diagnosed with prostate cancer at 75.

Other health considerations

None — Dave is healthy with a normal life expectancy.

__________________________________________________

What I would recommend for this patient

I'd discuss two reasonable paths: a targeted biopsy of the lesion, or a biomarker test first. Personally, I'd lean toward the targeted biopsy so we have definitive information.

Rationale

A PI-RADS 3 lesion is the true gray zone — the MRI is equivocal, meaning it can't reliably tell us whether significant cancer is there or not. In practice, a PI-RADS 3 lesion turns out to harbor clinically significant cancer roughly 15 to 25 percent of the time.

My preference here is a targeted biopsy. At 15 to 25 percent, the chance of finding something significant is high enough that I'd rather know definitively than infer — especially with a PSA climbing to 5.9 and a father with prostate cancer. A targeted biopsy samples the exact area the MRI flagged.

That said, a biomarker test is a reasonable alternative, particularly if a man is at higher risk from a biopsy or simply reluctant to have one. It gives an independent read: high risk pushes toward biopsy, low risk supports watching.

And if we watch, we watch closely — repeat PSA testing and MRI — because the family history keeps my guard up.

By Chad Ellimoottil, MD — urologist at Michigan Medicine specializing in prostate cancer detection.

Disclaimer: This information is for general educational purposes only and is not medical advice. Please consult a qualified healthcare professional about any medical condition, diagnosis, or treatment decision.