🫘 Renal Cystic Lesion Bosniak Classification (CT/MRI)
Look up the malignancy risk and management for a Bosniak 2019 renal cystic-lesion category (I–IV). Instant, browser-side.
Renal Cystic Lesion Bosniak Classification (CT/MRI)
Bosniak category (2019 version)
When to use
Translate a Bosniak category into a no-follow-up, imaging-follow-up or surgical pathway.
How it works
I/II benign (~0%) no follow-up; IIF probably benign (~5%) imaging follow-up; III indeterminate (~50%) surgery or active surveillance; IV malignant (~90%) surgery. Enhancement = CT ≥ 20 HU or MR ≥ 15%.
Key points
- The 2019 version unified the enhancement definition (CT ≥ 20 HU or MR ≥ 15%).
- Morphologic upgrade on follow-up strongly predicts malignancy and warrants reclassification.
- Biopsy of cystic lesions is generally not recommended (except category IV).
- Category III management balances surgery vs active surveillance by age and comorbidity.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.