Testing for penile cancer includes a physical examination, along with a carefully detailed history of health habits and past illnesses and treatments. Swelling at the end of the penis, especially when the foreskin is constricted, is another common sign that penile cancer may be present.

A biopsy is needed to make an accurate diagnosis. In this procedure, a small piece of the skin tissue is cut out and sent to a laboratory. There, a pathologist (a doctor specializing in laboratory diagnosis of diseases) looks at the tissue under a microscope to see whether cancer cells are present.