There is generalised enlargement of the lateral lobes of the prostate, and, to a lesser extent, of the median lobe, resulting in obstruction of the urethral opening. Nodularity is visible on the cut surface of the prostate. The bladder is dilated and the muscular wall thickened (hypertrophied), as seen in the exaggerated muscle bundles (trabeculation) and several outpouchings of the bladder mucosa (diverticula), which occur between the muscle bundles.