Too much tissue is produced, and tumors are formed. Tumors can be either benign or malignant . Benign tumors are not cancer. They do not spread to other parts of the body and are seldom a threat to life. Benign tumors can often be removed by surgery, and they are not likely to return.
Malignant tumors are cancer.
They can invade and destroy nearby healthy tissues and organs. Also, cancer cells can spread, or metastasize , to other parts of the body and form new tumors. Cancer that develops in a testicle is called testicular cancer. When testicular cancer spreads, the cancer cells are carried by blood or by lymph , an almost colorless fluid produced by tissues all over the body. The fluid passes through lymph nodes , which filter out bacteria and other abnormal substances such as cancer cells.