The breast is made up of milk producing glands that are arranged into units known as lobules. These glands are connected via a series of ducts that ultimately join up to form a common drainage path, terminating at the nipple. The nipple is surrounded by a ring of pigmented tissue known as the areola. Fibro-elastic and fatty tissue provide support for the rest of the structure and allow the breast to maintain its distinctive shape. The breast lies on top of the pectoral muscle, which in turn rests on the thoracic cage. Rough boundaries of the breast are as follows:
Superior aspect of the breast is bounded by the clavicle
Inferiorly by the inframamary crease ("bra line")
Medially by the sternum
Laterally by the axilla
Each breast contains a network of lymphatic tissue, ~ 90% of which drain into a lymph node group found in the ipsilateral axilla. The remaining 10% drain into the Internal Thoracic nodes, which are located beneath the sternum (not accessible by exam). Lymph drainage pathways are important in the setting of breast cancer, as this is usually the first site of spread (see below). For obvious reasons (i.e., milk production) woman have significantly more breast tissue then men.
Breast examination
Breast self-examination
Breast lumps ultrasound
Breast cancer laboratory tests
Breast lumps physical examination
Breast cancer physical examination
Breast cancer MRI
Paget's disease of the breast physical examination