MAMMOGRAPHY

Mammography is the most reliable means of detecting breast cancer before a mass can be palpated in the breast. Some breast cancers can be identified by mammography as early as 2 years before reaching a size detectable by palpation.
Although false-positive and false-negative results are occasionally obtained with mammography, the experienced radiologist can interpret mammograms correctly in approximately 90% of cases. For women with a history of mammographically occult lesions or otherwise at high risk for harboring cancer that is not detectable by mammogram, magnetic imaging resonance (MRI) and ultrasound may be warranted but they are not recommended for screening the general population.
Other than for screening, indications for mammography are as follows: (a) to evaluate each breast when a diagnosis of potentially curable breast cancer has been made, and at yearly intervals thereafter; (b) to evaluate a questionable or ill-defined breast mass or other suspicious change in the breast; (c) to search for an occult breast cancer in a woman with metastatic disease in axillary nodes or elsewhere from an unknown primary; (d) to screen at regular intervals a selected group of women who are at high risk for developing breast cancer (see below); (e) to screen women prior to cosmetic operations or prior to biopsy; and (f) to follow women who have been treated with breast-conserving surgery and radiation.
Patients with a dominant or suspicious mass must undergo biopsy regardless of mammographic findings. The mammogram should be obtained prior to biopsy so that other suspicious areas can be noted and the contralateral breast can be checked. Mammography is never a substitute for biopsy because it may not reveal clinical cancer in a very dense breast, as may be seen in young women with fibrocystic change, and it often does not reveal medullary-type histology breast cancer.