Anatomy and development (Figure 14.1)

• The breasts are large, modified sebaceous glands contained within the superficial fascia of the anterior chest wall.
  
• The average weight is 200–300 g during the menstruating years.
  
• Composed of 20% glands and 80% fat and connective tissue.
  
• Breast tissue is sensitive to the cyclic changes in hormonal levels – women often experience breast tenderness and fullness during the luteal phase of the cycle. Premenstrual symptoms are produced by an increase in blood flow, vascular engorgement, and water retention.
  
• Nearing the onset of puberty, the first change in the breast is the formation of the breast bud (see Chapter 21). The areola subsequently enlarges, and then the nipple begins to grow outwards.
  
• Estrogen is responsible for the initial stages of breast development, but further development requires adult levels of progesterone.

Physical examination

• Comprehensive breast examination is particularly important when symptoms are present.
  
• Inspection is the first step. This is usually done with the arms raised overhead, then with tension on the pectoralis muscles (by having the patient place her hands on her hips and press inward), and finally with the patient relaxed and leaning forward. These maneuvers accentuate skin and contour changes such as retraction, edema, or erythema, and nipple changes such as retraction, eczema, or erosion.
  
• Palpation is best performed with the patient in both sitting and supine positions. The examination is done in concentric circles, starting with the outermost breast tissue. The physician should attempt to elicit nipple discharge and examine the axilla carefully for adenopathy.

Benign breast disease