OHC’s leading cancer specialists, including our breast surgical oncologists, have extensive expertise in breast cancer in all its forms. As part of a breast cancer diagnosis, a pathologist will run tests on a breast tissue sample to help OHC’s multidisciplinary team make decisions about the best treatment plan for your individual type of cancer.
Common Categories of Breast Cancer
Most breast cancers are categorized as carcinomas. These tumors start in the cells that line organs and tissues in the body. When carcinomas start in the breast, they are specifically called an adenocarcinoma. Adenocarcinomas start in the milk ducts or the lobules that produce milk. Based on this, they can be categorized as ductal or lobular.
Breast cancer can also be classified as noninvasive or invasive
- Noninvasive (in situ)- the cancerous cells are still confined to their point of origin.
- Invasive (infiltrating)- cancer has spread to surrounding tissues.
Ductal Carcinoma In Situ
Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer contained in the lining of the breast milk duct. This is also referred to as stage 0 breast cancer.
Invasive Ductal Carcinoma
Invasive ductal carcinoma, or infiltrating ductal carcinoma (IDC), means that abnormal cells that originated in the lining of the breast’s milk duct have invaded surrounding tissue. Over time, IDC can potentially spread to the nearby lymph nodes and possibly to other areas of the body. Invasive ductal carcinoma is the most common type of breast cancer, accounting for approximately 80 percent of all breast cancers.
Invasive Lobular Carcinoma
Invasive lobular carcinoma (ILC) starts in the milk-producing glands (lobules) and can spread to other parts of the body. Invasive lobular carcinoma is the second most common form of invasive breast cancer, accounting for 10-to-15 percent of breast cancer cases. Compared to ductal carcinoma, lobular carcinomas may be harder to see on a mammogram.
Less Common Types of Breast Cancer
Angiosarcoma is a type of cancer that starts in the cells that line blood vessels. This type of breast cancer is rare in the breast.
In invasive cribriform carcinoma, the cancer cells invade the connective tissues of the breast in nest-like formations between the ducts and lobules. Within the tumor, there are distinctive holes in between the cancer cells, making it look something like Swiss cheese. Invasive cribriform carcinoma is usually low grade, meaning that its cells look and behave somewhat like normal, healthy breast cells.
Inflammatory Breast Cancer
This is a rare type of breast cancer that accounts for one-to-five percent of all breast cancers in the U.S. Inflammatory breast cancer may present similarly to a breast infection with redness and swelling rather than a mass. This is because the cancer cells are blocking lymphatic vessels in the skin and breast tissue, causing a buildup of fluid (lymph), which can make the breast appear red, dimpled (like the skin of an orange peel), or painful to touch.
Male Breast Cancer
In the U.S., less than one percent of all breast cancer cases occur in men. Breast development stops in men during puberty because of high testosterone levels and low estrogen levels, but some undeveloped milk ducts remain. The most common sign of male breast cancer is a painless lump in the breast.
This rare breast cancer is a subtype of invasive ductal carcinoma. It is named for its soft, fleshy resemblance to the brain’s medulla. It does not normally grow quickly or spread into the lymph nodes.
Mucinous carcinoma (or colloid carcinoma) is a rare form of invasive ductal carcinoma where the tumor is made up of abnormal cells found in pools of mucin. Mucin is found in mucus, which lines our body’s digestive tract, liver, lungs, and other organs. In mucinous carcinoma, mucin becomes part of the tumor and surrounds the breast cancer cells. This tends to be a less aggressive type of breast cancer, and in general, is less likely to spread to the lymph nodes compared to other types of breast cancer.
Paget’s Disease of the Nipple
This type of breast cancer starts on the nipple and then spreads to the areola, the dark circle around the nipple. Because of this, a woman might notice changes like flaking or scaling on the nipple or areola. Many women who have Paget’s disease of the nipple also have an underlying breast cancer.
Invasive papillary carcinoma is another rare type of invasive ductal carcinoma that is made up of small, finger-like projections. In most cases, these types of tumors are diagnosed in older, postmenopausal women and ductal carcinoma in situ is also present.
Phyllodes tumors are rare breast tumors. These tumors develop in the connective tissue (stroma) of the breast and grow in a leaflike pattern. Although phyllodes tumors tend to grow quickly, they rarely spread outside the breast. They can be either benign (non-cancerous) or malignant.
Tubular carcinomas are usually small and made up of tube-shaped structures called “tubules.” These tumors tend to be low-grade, meaning that their cells look more like normal, healthy cells and they tend to grow slowly. It is a subtype of invasive ductal carcinoma.