Stage III penile cancer is divided into stage IIIa and stage IIIb. In stage IIIa, cancer has spread to one lymph node in the groin and (1) to connective tissue just under the skin of the penis; cancer may have spread to lymph vessels or blood vessels, or the tumor cells may look very different from normal cells under a microscope; or (2) through connective tissue to erectile tissue (spongy tissue that fills with blood to make an erection); or (3) beyond erectile tissue to the urethra. In stage IIIb, cancer has spread to more than one lymph node on one side of the groin or to lymph nodes on both sides of the groin, and (1) to connective tissue just under the skin of the penis; cancer may have spread to lymph vessels or blood vessels, or the tumor cells may look very different from normal cells under a microscope; or (2) through connective tissue to erectile tissue (spongy tissue that fills with blood to make an erection); or (3) beyond erectile tissue to the urethra.