Prostate cancer cells. Coloured scanning electron micrograph (SEM) of prostate cancer cells in the final stage of cell division (cytokinesis). The cells' cytoplasm has divided and they are joined by a long cytoplasmic bridge (green). Prostate cancer is one of the most common male cancers, affecting the prostate gland, which lies below the bladder. The cancer occurs mainly in the elderly. It obstructs the neck of the bladder and impairs urination. Treatment involves removal of the gland followed by radiotherapy. Cancer cells are large and divide rapidly in a chaotic manner, forming clumps which can invade and destroy surrounding tissues. Magnification unknown.