About The Breast
The breast is mostly made up of different tissue, ranging from very fatty tissue to very dense tissue. Within this tissue is a network of lobes, which are made up of small, tube-like structures called lobules that contain milk glands.
Tiny ducts connect the glands, lobules, and lobes, carrying the milk from the lobes to the nipple. The nipple is located in the middle of the areola, which is the darker area that surrounds the nipple. Blood and lymph vessels also run throughout the breast.
Blood nourishes the cells, and the lymphatic system drains bodily waste products. The lymph vessels connect to lymph nodes, which are tiny, bean-shaped organs that help fight infection.
What is Breast Cancer?
Breast cancer begins when healthy cells in the breast change and grow out of control, forming a mass called a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can spread to other parts of the body. A benign tumor can grow but does not spread to other parts of the body, and it is rarely life-threatening.
Types of Breast Cancer
Breast cancer can be invasive or noninvasive. Invasive breast cancer is cancer that spreads into surrounding tissues. Noninvasive breast cancer does not go beyond the milk ducts or lobules in the breast. Most breast cancers start in the ducts, called ductal carcinoma, or in the lobules, called lobular carcinoma.
A pathologist determines whether a tumor removed during a biopsy is ductal or lobular cancer.
A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. If the disease has spread outside the duct or lobule and into the surrounding tissue, it is called invasive or infiltrating ductal or lobular carcinoma.
Cancer that is located only in the duct or lobule is called in situ, meaning “in place,” and is noninvasive. Most in situ breast cancers are ductal carcinoma in situ (DCIS). DCIS is often treated with surgery, radiation therapy, and hormonal therapy.
Lobular carcinoma in situ (LCIS) is not considered cancer and is usually monitored by a doctor with regularly scheduled examinations and imaging tests.
LCIS in one breast is a risk factor for developing invasive breast cancer in both breasts. To reduce this risk, LCIS is sometimes treated with hormonal therapy. Other less common types of breast cancer include medullary, mucinous, tubular, metaplastic, and papillary breast cancer, as well as other even rarer types.
Inflammatory breast cancer is a faster growing type of cancer that accounts for about 1% to 5% of all breast cancers. At first it may be misdiagnosed as a breast infection because there is often swelling of the breast and redness of the breast skin that starts suddenly, and there may be no breast mass or lump.
Paget’s disease is a type of cancer that begins in the ducts of the nipple. The skin often appears scaly and may be itchy. Although it is usually in situ, it can also be an invasive cancer.