Bosniak Classification and Management of Cystic Renal Masses
Category I- Ignore
Hairline thin wall
No septa, calcifications or solid components
Water attenuation
No enhancing components
Category II- Ignore
Few hairline thin septa can have perceived but not measurable enhancement
Fine or short slightly thickened calcifications
Well defined, homogeneously high attenuation masses
Category II-F- Observe
Multiple hairline thin septa can have perceived but not measurable enhancement
Minimal smooth wall or septal thickening can have perceived but not measurable enhancement
Thick or nodular calcifications
No enhancing soft tissue components
Well defined, homogeneously high attenuation masses > 3 cm without enhancement
Category III- Surgery
Thickened or smooth walls or septa with measurable enhancement
Category IV- Surgery
Same as category III but with enhancing soft tissue components adjacent to or separate from the wall or septa.
Hairline thin wall
No septa, calcifications or solid components
Water attenuation
No enhancing components
Category II- Ignore
Few hairline thin septa can have perceived but not measurable enhancement
Fine or short slightly thickened calcifications
Well defined, homogeneously high attenuation masses
Category II-F- Observe
Multiple hairline thin septa can have perceived but not measurable enhancement
Minimal smooth wall or septal thickening can have perceived but not measurable enhancement
Thick or nodular calcifications
No enhancing soft tissue components
Well defined, homogeneously high attenuation masses > 3 cm without enhancement
Category III- Surgery
Thickened or smooth walls or septa with measurable enhancement
Category IV- Surgery
Same as category III but with enhancing soft tissue components adjacent to or separate from the wall or septa.