Cancer begins when healthy cells change and grow out of control, forming a mass called a malignant tumor. Malignant means that the tumor is cancerous and can grow and spread to other parts of the body. There are also benign tumors of the penis that are not cancers. They can grow but do not spread.

Penile cancer is a rare form of cancer that occurs mostly in uncircumcised men. Uncircumcised means that a man still has the piece of skin called the foreskin covering the head of the penis. Circumcision is the removal of the foreskin and may reduce the risk of penile cancer.

Types of penile cancer
There are several types of penile cancer, including:

Epidermoid/squamous cell carcinoma. Ninety-five percent (95%) of penile cancer is epidermoid, or squamous cell, carcinoma. This means that the cells look like the tissues that make up skin when seen through a microscope. Squamous cell carcinoma can begin anywhere on the penis. But it usually develops on or under the foreskin. When found at an early stage, epidermoid carcinoma can usually be cured.

Basal cell carcinoma. Basal cells can sometimes become cancerous. These are round cells located under the squamous cells in a layer of skin called the lower epidermis. Basal cell carcinoma is a type of non-melanoma skin cancer. Less than 2% of penile cancers are basal cell cancers.

Melanoma. The deepest layer of the epidermis contains scattered cells called melanocytes. These cells make the melanin that gives skin color. Melanoma starts in melanocytes. It is the most serious type of skin cancer. This type of cancer sometimes occurs on the surface of the penis. Learn more about melanoma.

Sarcoma. About 1% of penile cancers are sarcomas. Sarcomas develop in the tissues that support and connect the body, such as blood vessels, muscle, and fat. Learn more about sarcoma.