Evaluation of Breast Disorders
Breast symptoms (eg, masses, nipple discharge, pain) 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 or confirm cancer.
Principles of examination are similar for physician and patient.
Breasts are inspected for asymmetry in shape, nipple inversion (retraction), bulging, and skin dimpling (see Figure: Breast examination. A and B for usual positions). 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 Figure: Breast examination. 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 ligament.
The nipples are squeezed to check for a discharge and, if present, to determine its source (eg, whether it is multiductal).
The axillary and supraclavicular lymph nodes are most easily examined with the patient seated or standing (see Figure: Breast examination. 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 Figure: Breast examination. 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 Figure: Breast examination. 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 may mean that a biopsy is needed, even if imaging shows no abnormalities.
The following findings are of particular concern:
A mass that feels distinctly different from other breast tissue
A mass that is fixed to the skin or chest wall
A persistent mass
Persistent breast swelling
Peau d'orange (pitting, puckering, reddening, thickening, or dimpling in the skin of the breast)
Scaly skin around the nipple
Changes in the shape of the breast
Changes in the nipple (eg, retraction)
A unilateral discharge from the nipple, especially if it is bloody and/or occurs spontaneously
Imaging tests are used for
All women should be screened for breast cancer. All professional societies and groups agree on this concept, although they differ on the recommended age at which to start screening and the precise frequency of screening.
Screening mammography recommendations for average-risk women vary but generally, screening starts at age 40 or 50 and is repeated every year or two until age 75 or until life expectancy is < 10 yr (see Table: Recommendations for Breast Cancer Screening Mammography in Women With Average Risk). 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. Mammography is less sensitive in women with dense breast tissue; some states mandate informing patients that they have dense breast tissue when it is detected by screening mammography.
Recommendations for Breast Cancer Screening Mammography in Women With Average Risk
In mammography, low-dose x-rays of both breasts are taken in 1 (oblique) or 2 views (oblique and craniocaudal). Only about 10 to 15% 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 digital 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.
Breast tomosynthesis (3-dimensional mammography) done with digital mammography increases the rate of cancer detection slightly and decreases the rate of recall imaging; this test is helpful for women with dense breast tissue. However, the test exposes women to almost twice as much radiation as traditional mammography.
Diagnostic mammography is used to do the following:
Diagnostic mammography requires more views than screening mammography. Views include magnified views and spot compression views, which provide better visualization of suspect areas.
Ultrasonography can be used to do the following:
MRI can be used to do the following:
For women at high risk of breast cancer (eg, with a BRCA gene mutation or a calculated lifetime risk of breast cancer of ≥ 20%), screening should include MRI in addition to clinical breast examination and mammography. MRI is not considered appropriate for screening women with average or slightly increased risk.
If women have dense or heterogeneously dense breast tissue, supplemental screening imaging (eg, ultrasonography plus mammography) should be discussed.