Cancerous tumours of the penis

A cancerous tumour of the penis can grow into nearby tissue and destroy it. The tumour can also spread (metastasize) to other parts of the body. Cancerous tumours are also called malignant tumours. There are several types of penile cancer.

Squamous cell carcinoma (SCC) is the most common malignant tumour of the penis. Over 95% of penile cancers are SCC. SCC begins in the main type of skin cells called squamous cells. These cells are flat and thin.

SCC can develop anywhere on the penis, but it most often develops on the foreskin or on the head of the penis (glans). It can develop from the precancerous condition called penile intraepithelial neoplasia (PeIN). SCC is typically slow growing.

SCC of the penis is described as human papillomavirus (HPV)-associated or HPV-independent, based on whether it is linked to HPV infections. Each type of SCC has different subtypes based on how the tumour looks under a microscope (called histologic subtypes).

HPV-associated SCC is mainly basaloid SCC. Other subtypes include:

• warty SCC
• clear cell SCC
• lymphoepithelioma-like SCC
• mixed SCC that are mainly in warty-basaloid form

HPV-independent SCC is usually keratinizing SCC, which is when the squamous cells make a tough, fibrous protein (keratin). Other subtypes include:

• verrucous SCC, also known as verrucous carcinoma
• papillary SCC
• sarcomatoid SCC
• mixed SCC

The following cancerous tumours of the penis are rare.

Melanoma begins in the cells of the skin that produce pigment (melanocytes). It most often develops in areas of the skin that are exposed to the sun. But it may also develop in other areas such as the penis.

Basal cell carcinoma is found in the basal cells (the deepest layer of skin cells) of the penis.

Sarcoma is found in soft tissue cells of the penis.

Adenocarcinoma (also called Paget disease of the penis) starts in sweat glands of the penis skin.