Breast Disorders

Breast symptoms (eg, pain, lumps, nipple discharge) are common, accounting for > 15 million physician visits/yr. Although > 90% of symptoms have benign causes, breast cancer is always a concern. Because breast cancer is common and may mimic benign disorders, the approach to all breast symptoms and findings is to conclusively exclude cancer.

History includes duration of symptoms; relation of symptoms to menses and pregnancy; presence and type of pain, discharge, and skin changes; use of drugs, including hormone therapy; personal and family history of breast cancer; and date and results of last mammogram.

Breast examination: Principles of examination are similar for physician and patient. Breasts are inspected for asymmetry in shape, nipple inversion, bulging, and dimpling (see Fig. 1: Breast Disorders: Breast Cancer Risks A and B). Although size differential is common, each breast should have a regular contour. An underlying cancer is sometimes detected by having the patient press both hands against the hips or the palms together in front of the forehead (see Fig. 1: Breast Disorders: Breast Cancer Risks C and D). In these positions, the pectoral muscles are contracted, and a subtle dimpling of the skin may appear if a growing tumor has entrapped a Cooper's ligament.

The axillary and supraclavicular lymph nodes are most easily examined with the patient seated or standing (see Fig. 1: Breast Disorders: Breast Cancer Risks E). Supporting the patient's arm during the axillary examination allows the arm to be fully relaxed so that nodes deep within the axilla can be palpated.

The breast is palpated with the patient seated and again with the patient supine, the ipsilateral arm above the head, and a pillow under the ipsilateral shoulder (see Fig. 1: Breast Disorders: Breast Cancer Risks F). The latter position is also used for breast self-examination; the patient examines the breast with her contralateral hand. Having the patient roll to one side, so that the breast on the examined side falls medially, may help differentiate breast and chest wall tenderness because the chest wall can be palpated separately from breast tissue.

The breast should be palpated with the palmar surfaces of the 2nd, 3rd, and 4th fingers, moving systematically in a small circular pattern from the nipple to the outer edges (see Fig. 1: Breast Disorders: Breast Cancer Risks G). Precise location and size (measured with a caliper) of any abnormality should be noted on a drawing of the breast, which becomes part of the patient's record. A written description of the consistency of the abnormality and degree to which it can be distinguished from surrounding breast tissue should also be included. Detection of abnormalities during physical examination largely determines whether a biopsy is needed, even if a subsequent mammogram shows no abnormalities.

Testing: Imaging tests are used for screening and for evaluation of breast abnormalities. Annual screening mammography is recommended for women ≥ 50 yr and sometimes for women 40 to 50 yr. Mammography is more effective in older women because with aging, fibroglandular tissue in breasts tends to be replaced with fatty tissue, which can be more easily distinguished from abnormal tissue. Low-dose x-rays of both breasts are taken in 1 (oblique) or 2 views (oblique and craniocaudal). Only about 10% of abnormalities detected result from cancer. Accuracy of mammography depends partly on the techniques used and experience of the mammographer; false-negative results may exceed 15%. Some centers use computer analysis of digitized mammography images to help in diagnosis. Such systems are not recommended for stand-alone diagnosis, but they appear to improve sensitivity for detecting small cancers by radiologists.

Mammography is also used diagnostically to evaluate lumps, pain, and nipple discharge. It can determine size and location of a lesion and provide images of surrounding tissues and lymph nodes. Diagnostic mammography requires more views than screening mammography. For biopsy of a lesion seen on a mammogram but not detectable during physical examination, 2 needles or wires can be inserted via radiologic guidance to localize the lesion. The excised specimen should be x-rayed, and the x-ray compared with the prebiopsy mammogram to determine whether the lesion has been removed. Mammography is repeated when the breast is no longer tender, usually 6 to 12 wk after biopsy, to confirm removal of the lesion.

MRI is thought to be more accurate than clinical breast examination or mammography for screening women with a high (eg, > 15%) risk of breast cancer, such as those with a BRCA gene mutation. It is not considered appropriate for screening women with average or slightly increased risk. Because MRI can accurately determine tumor size, chest wall involvement, and presence of multiple tumors, it is often used in evaluation after breast cancer is diagnosed. Use of MRI to identify axillary node involvement is under study.