The diagram depicts the zonal morphology relevant to the locations where disease arises. The prostate gland can be viewed as having 4 major zones. The outer zone is called the peripheral zone, accounts for 70% of the parenchyma. Inward of the peripheral zone is the central zone that accounts for 25% of the parenchyma. The periurethral zone is called the transitional zone and fibromuscular zone (anterior layer) account for the remaining 5% of parenchyma. The art piece shows carcinoma (bright lime green) arising from the peripheral zone which is the characteristic site of origin of this disease.