mammography

Radiologic examination of the female breast with equipment and techniques designed to screen for cancer. [mammo- + G. grapho, to write] M. can detect carcinoma of the breast sometimes as early as 2 years before it becomes palpable and in many cases before lymph node metastasis has occurred. Mammographic findings that strongly suggest carcinoma are microcalcifications and ill-defined densities within breast tissue. These findings are not specific, however, and the cumulative probability of a woman's having a false-positive mammogram during 10 years of annual examinations approaches 50%. Scintimammography after intravenous injection of Tc-99m sestamibi may be used to follow up an equivocal mammogram. Positron emission tomography (PET) has shown promise in discriminating between benign and malignant breast masses as well as in detecting axillary lymph node metastases in patients with newly diagnosed breast cancer and distant metastases in patients with advanced or recurrent breast carcinoma. Because of the high cost of this procedure, its use is currently limited to high-risk subjects and those with dense breasts. The value of m. in the early detection of breast cancer is well established for women of average risk aged 50–69 years. For this group, annual m. reduces breast cancer mortality by 30–40%. Analysis of numerous clinical studies has revealed that mammograms may not save lives for healthy women under 50 (only 17% of all breast cancers occur in women under 40). The higher density of breast tissue in younger women limits the ability of radiography to identify tumors in women aged 40–50, for whom ultrasonography is preferred in evaluation of palpable breast lesions. Research has suggested that for a small fraction of women, exposure to radiation during m. may actually trigger breast cancer. The American Cancer Society, the National Cancer Institute, and the American College of Radiology recommend a baseline mammogram for all women by age 40 and annual mammograms after age 50. Mammograms should begin at age 25 for women who are at special risk because of family history. Because some 10% of breast cancers that can be felt on examination are missed by m., annual examination of the breasts by a physician is also recommended. Surveillance by the Food and Drug Administration has shown an improvement in the sensitivity of mammograms during the past 5 years, largely because of improvements in screen and film systems. A digital scanning technique approved in 1998 further enhances the detection of microcalcifications and spiculated masses on m.. However, m. remains a screening procedure, and diagnosis of breast lesions depends on physical examination and biopsy findings. Federal law requires all facilities in the U.S. that perform m. to provide each examinee with a report of the results in clear, simple language within 30 days after the examination, besides a detailed report to the physician who ordered the examination. See Also carcinoma of the breast.

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mam·mog·ra·phy -fē n, pl -phies X-ray examination of the breasts (as for early detection of cancer)

mam·mo·graph·ic .mam-ə-'graf-ik adj

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n.

X-ray examination of the female breast. Using low-energy X-rays, fine details of breast tissue can be visualized, particularly the presence of calcification or soft tissue masses enabling the early diagnosis of breast cancer. See also Forrest screening.

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mam·mog·ra·phy (mə-mogґrə-fe) radiography of the mammary gland.