Types of breast cancer in men

Ductal carcinoma in situ (DCIS)

In DCIS (also known as intraductal carcinoma), cancer cells form in the breast ducts but do not grow through the walls of the ducts into the fatty tissue of the breast or spread outside the breast. DCIS accounts for about 1 in 10 cases of breast cancer in men. It is almost always curable with surgery.

Infiltrating (or invasive) ductal carcinoma (IDC)

This type of breast cancer breaks through the wall of the duct and grows through the fatty tissue of the breast. At this point, it can spread (metastasize) to other parts of the body. At least 8 out of 10 male breast cancers are IDCs (alone or mixed with other types of invasive or in situ breast cancer). 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. This is different from Paget disease as described below.

Infiltrating (or invasive) lobular carcinoma (ILC)

This type of breast cancer starts in the breast lobules (collections of cells that, in women, produce breast milk) and grows into the fatty tissue of the breast. ILC is very rare in men, accounting for only about 2% of male breast cancers. This is because men do not usually have much lobular tissue.

Lobular carcinoma in situ (LCIS)

In LCIS, abnormal cells form in the lobules, but they do not grow into the fatty tissue of the breast or spread outside the breast. Although LCIS is sometimes grouped with DCIS as a type of non-invasive breast cancer, most breast specialists think it is a risk factor for developing breast cancer rather than a true non-invasive cancer. As with invasive lobular carcinoma, LCIS is very rare in men.

Paget disease of the nipple

This type of breast cancer starts in the breast ducts and spreads to the nipple. It may also spread to the areola (the dark circle around the nipple). The skin of the nipple usually appears crusted, scaly, and red, with areas of itching, oozing, burning, or bleeding. The fingertips can be used to detect a possible lump within the breast.

Paget disease may be associated with DCIS or with infiltrating ductal carcinoma. It accounts for about 1% of female breast cancers and a higher percentage of male breast cancers.

Inflammatory breast cancer

Inflammatory breast cancer is an aggressive, but rare type of breast cancer. It causes the breast to be swollen, red, warm and tender rather than forming a lump. It can be mistaken for an infection of the breast. This is very rare in men.