How is reporting prostate biopsies Gleason's?

• According to the WHO 2016 recommendations • Each positive site GS (modified GS WHO2016) • Composed of – Most extensive AND – Most agressive (highest grade) • Irrespectively of its extent (no 5% rule) Reporting minor high grade patterns, same rules PB and RP? • Only validation for PB • If only 2 patterns, record the HP even if focal • GG3 + 5% GG4= 3+4 Reporting minor high grade patterns • If 3 patterns and the HP is the least common pattern yet still >5% then report the HP as the secondary grade • 50% GG3+ 30% GG4+20% GG 3+5=8