Dictionary

breakbone fever See dengue fever.

breast The front of the chest or the mammary gland. The mammary gland is a milk-producing gland that is largely composed of fat. Within the mammary gland are sac-like structures called lobules, which produce the milk, as well as a complex network of branching ducts. These ducts exit from the lobules at the nipple. The…

breast, infiltrating ductal carcinoma of the One of several recognized specific patterns of breast cancer that begins in the cells that form the ducts of the breast. The most common form of breast cancer, it may appear as a smooth-edged lump in the breast. On physical examination, this lump usually feels much harder or firmer…

breast, infiltrating lobular carcinoma of the The second most common invasive breast cancer. Infiltrating lobular carcinoma starts in the lobules, the glands that secrete milk, and then infiltrates surrounding tissue. Lobular carcinoma can occur in more than one site in the breast or in both breasts at the same time (a bilateral lobular carcinoma).

breast, Paget’s disease of The combination of scaly skin on the nipple that resembles eczema and an underlying cancer of the breast. The nipple is inflamed because of the presence of Paget’s cells, large, irregular cells that are almost always associated with cancer in the breast. In Paget’s disease, the nipple and areola (the area…

breast absence See amastia.

breast augmentation Artificial enlargement of the breasts. Breast augmentation may be done by insertion of a silicone bag (prosthesis) under the breast (submammary) or under the breast and chest muscle (subpectoral), after which the bag is filled with saline solution. This prosthesis expands the breast area to give the appearance of a fuller breast (increased…

breast cancer A common form of cancer that begins in the breast. There are many types of breast cancer, and they differ in their capability of spreading to other body tissues (metastasis). Breast cancer can occur in both men and women, although it is more common in women. Some forms of breast cancer are genetic…

breast cancer, familial A form of breast cancer that tends to occur in members of the same family. A number of factors have been identified as increasing the risk of breast cancer. One of the strongest is a family history of breast cancer in a relative. About 15 to 20 percent of women with breast…

braces, dental Devices used by orthodontists to move the position teeth or adjust underlying bone. Temporomandibular joint (TMJ) problems can also sometimes be corrected with dental braces. Teeth can be moved by removable appliances or by fixed braces. If there is crowding of teeth, some teeth may need to be extracted before braces are applied….

brachial artery The artery that runs from the shoulder down to the elbow. See also brachial vein.

brachial plexus A bundle of nerves that begins in the back of the base of the neck and extends through the armpit. It is formed by the union of portions of the fifth through eighth cervical spinal nerves and the first thoracic spinal nerve. Damage to the brachial plexus can affect nerves responsible for muscle…