Merck Manuals, an online medical library, reports that 213,000 women were diagnosed with breast cancer in the United States in 2006. Breast cancer is the second most common type of cancer, and the second leading cause of death due to cancer. There are multiple different types of breast cancer; the type is based on the type of cell that is the origin of the tumor, the symptoms caused by the cancer or other specific characteristics of the cancer.
Ductal Carcinoma
According to the National Cancer Institute, the most common type of breast cancer is ductal carcinoma, which begins in the milk ducts of the breast. Merck Manuals adds that about 90 percent of all breast cancers are of this type. The Mayo Clinic reports that this type of cancer starts in the cells that line the milk ducts which carry milk from the milk-producing glands to the nipple.
Lobular Carcinoma
Another type of breast cancer is lobular carcinoma. It begins in the milk-producing glands, also called "lobules," which are connected to the milk ducts.
Sarcoma
Sarcoma is a very rare type of breast cancer. This tumor starts either in the fatty tissue of the breast, or in the connective tissue. According to the Mayo Clinic, examples of sarcomas include phyllodes tumors, which are typically large masses that grow very fast, and angiosarcomas.
Paget's Disease of the Nipple
This type of breast cancer is actually a subtype of ductal breast cancer, according to Merck Manuals. The initial symptoms of Paget's disease are crusty skin on the nipple, or a discharge from the nipple.
Inflammatory Breast Cancer
Inflammatory breast cancer is so called because of the symptoms of the cancer, not the type of tissue it affects. In this type of cancer, the breast tissue becomes inflamed and may feel swollen, warm and/or red. This type tumor often spreads to the lymph nodes underneath the arm. There may be no lump detectable in the breast itself because the cancerous cells are spread throughout the breast tissue.
Receptor-Positive Breast Cancer
The National Cancer Institute reports that some types of breast cancer need specific hormones to grow, and thus have a receptor to bind and internalize that hormone. Common hormones that help certain cancers grow are estrogen, progesterone or both.
