Laser therapy: A treatment using intense beams of light to precisely cut, burn, or destroy tissue. The term laser is an acronym for "light amplification by stimulated emission of radiation."

Liquid nitrogen: Nitrogen is typically found in its gaseous form. To become a liquid, nitrogen gas must release great amounts of heat, becoming super-cooled to about minus 200 degrees Celsius. It may be applied to diseased or cancerous tissue to kill the cells. Tissue that has been frozen falls off from the surrounding tissue.

Local therapy: Treatment that affects cells in the tumor and the area close to it.

Lymph: The almost colorless fluid that travels through the lymphatic system and carries cells that help fight infection and disease.

Lymphatic system: The system of nodes and vessels that carry lymph throughout the body.

Lymphedema: A condition in which excess fluid collects in tissue and causes swelling. It may occur in the arm or leg after lymph vessels or lymph nodes in the underarm or groin are removed.

Lymph nodes: Glands that produce lymph and that filter out harmful agents (such as bacteria, viruses, and cancer cells).