Breast Cancer in Men

DCIS (also known as intraductal carcinoma) is considered non-invasive or pre-invasive breast cancer.

In DCIS, cells that line the ducts have changed to look like cancer cells. But the cells have not spread (invaded) through the walls of the ducts into the surrounding tissue of the breast or spread outside the breast.

DCIS is considered a pre-cancer because sometimes it can go on to become an invasive cancer. But there is no sure way to know which ones will and which ones won’t.

DCIS accounts for about 1 in 10 cases of breast cancer in men. It is almost always curable with surgery.

Invasive (or infiltrating) ductal carcinoma (IDC) starts in duct cells in the breast and invades into deeper layers of breast tissue. It can also spread to other parts of the body through the lymph system or bloodstream.

This is by far the most common type of breast cancer in men. At least 8 out of 10 male breast cancers are IDCs.

Because the male breast is much smaller than the female breast, all male breast cancers start relatively close to the nipple, so they are more likely to spread to the nipple.

Special subtypes of IDC

There are some special subtypes of IDC. These are often named after features of the cancer cells, like the ways the cells are arranged. They are much less common than standard IDC.

Some of these tend to have a better outlook (prognosis) than standard IDC:

• Adenoid cystic (or adenocystic) carcinoma
• Low-grade adenosquamous carcinoma (a type of metaplastic carcinoma)
• Medullary carcinoma
• Mucinous (or colloid) carcinoma
• Papillary carcinoma
• Tubular carcinoma

Some subtypes have the same or possibly a worse prognosis than IDC:

• Metaplastic carcinoma (including spindle cell and squamous, except for low-grade adenosquamous carcinoma)
• Micropapillary carcinoma
• Mixed carcinoma (has features of both IDC and ILC)

In general, all of these subtypes are still treated like standard IDC.

Invasive lobular carcinoma (ILC) starts in the cells lining the lobules. Like IDC, it invades into deeper layers of breast tissue and can spread to other parts of the breast and body.

ILC is rare in men. This is because men do not usually have much (if any) lobular breast tissue.

This type of breast cancer starts in the breast duct and spreads to the nipple. It may also spread to the areola (the dark circle around the nipple).

The skin of the nipple often looks crusted, scaly, and red, with areas of itching, oozing, burning, or bleeding. There may also be an underlying lump.

Paget disease is often found along with either DCIS or infiltrating ductal carcinoma.

This type of breast cancer is rare in both men and women.

Inflammatory breast cancer is a fast-growing but rare type of invasive ductal carcinoma in which the cancer cells block up the lymph vessels. This can make the breast swollen, red, warm, and tender rather than forming a lump. It can be mistaken for an infection in the breast tissue.

This type of breast cancer is very rare in men.

Gynecomastia is the most common male breast disorder. It is not a tumor but rather an increase in the amount of a man's breast tissue.

Usually, men have too little breast tissue to be felt or noticed. Gynecomastia can appear as a button-like or disk-like growth under the nipple and areola (the darker circle around the nipple), which can be felt and sometimes seen. Some men have more severe gynecomastia and they may appear to have small breasts.

Although gynecomastia is much more common than breast cancer in men, both can be felt as a growth under the nipple, so it's important to have any such lumps checked by your doctor.

Causes of gynecomastia

Men's glands normally make some estrogen (the main female hormone), but not enough to cause breast growth.

Gynecomastia is common among teenage boys because the balance of hormones in the body changes during adolescence. It is also common in older men due to changes in their hormone balance.

Other causes of gynecomastia include:

• Tumors or diseases of certain endocrine (hormone-producing) glands, which can cause the body to make more estrogen.
• Liver disease, which can affect hormone metabolism and change the balance of hormones.
• Having excess body weight, which can lead to higher estrogen levels.
• Certain medicines, including some used to treat ulcers and heartburn, high blood pressure, heart failure, and psychiatric conditions. If you have gynecomastia, ask your doctor if any medicines you are taking might be causing it.
• Klinefelter syndrome, a rare genetic condition that can cause gynecomastia as well as increase a man's risk of developing breast cancer.

There are many types of benign breast tumors (abnormal lumps or masses of tissue), such as papillomas and fibroadenomas. Benign tumors do not spread outside the breast and are not life-threatening.

Benign breast tumors are common in women but are very rare in men.