Prostate tumour. Coloured ultrasound scan of a section through the pelvis of a 52 year old man with an adenoma of the prostate gland (dark blue, centre). The black areas are the bladder, which is being prevented from emptying fully by the enlarged prostate pressing on the urethra, the tube that urine passes through. Adenoma is a benign (non-cancerous) tumour that is most common in men over 50 years of age. Treatment is either with drugs to make the prostate shrink, or the surgical removal of the prostate.