Types of Breast Cancer
Adenocarcinoma:
Nearly all breast cancers start in the ducts or lobules of the breast. Because this is glandular tissue, they are called adenocarcinomas, a term applied to cancers of glandular tissue anywhere in the body. The 2 main types of breast adenocarcinomas are ductal carcinomas and lobular carcinomas.
Ductal carcinoma in situ (DCIS):
DCIS is an uncommon type of breast adenocarcinoma in men (about 10%). Cancer cells fill the ducts but do not invade through the walls of the ducts into the fatty tissue of the breast or spread outside the breast. It is almost always curable with surgery.
In situ is the term used for the early stage of cancer, when it is confined to the immediate area where it began. Specifically in breast cancer, in situ means that the cancer remains confined to ducts (ductal carcinoma in situ) or lobules (lobular carcinoma in situ). It has not invaded surrounding fatty tissues in the breast nor spread to other organs in the body.
Infiltrating (or invasive) ductal carcinoma (IDC):
Starting in a duct of the breast, this type of adenocarcinoma breaks through the wall of the duct and invades the fatty tissue of the breast. At this point, it can metastasize (or spread) to other parts of the body. IDC (alone or mixed with other types of invasive or in situ breast cancer) accounts for 80% to 90% of male breast cancers.
Lobular breast cancers in men are very rare, accounting for only 2% of adenocarcinomas. This is because men do not usually have lobular tissue, the milk-producing glands.
Paget disease of the nipple:
This type of breast cancer starts in the breast ducts and spreads to the skin of 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. Using the fingertips, a lump may be detected within the breast. If no lump can be felt, the prognosis (outlook for survival) is generally good. Paget disease may be associated with in situ carcinoma or with infiltrating breast carcinoma. It accounts for about 1% of female breast cancers and a higher percentage of male breast cancers. Because the male breast is much smaller than the female breast, all male breast cancers start relatively close to the nipple, so spread to the nipple is more likely.
