If the cells keep dividing when new cells are not needed, they form too much tissue. Excess tissue can form a mass, called a tumor. Excess tissue can be benign or malignant. Benign tissue is not cancer. The cells do not invade nearby tissue or spread to other parts of the body.
Malignant tissue is cancer.
The cancer cells divide out of control. They can invade and destroy nearby healthy tissue. The spread of cancer is called metastasis. In BPH, the prostate grows larger and pushes against the urethra and bladder, blocking the normal flow of urine. Although this condition is seldom a threat to life, it may require treatment to relieve symptoms.