Mammographic features of malignancy found during screening.

Mammographic detection of nonpalpable breast cancer permits earlier diagnosis and reduces mortality from the disease. The increasing emphasis on screening asymptomatic women with mammography is placing the responsibility for tumor detection more and more in the hands of the radiologist. While it has long been known that cancer can present mammographically with less than textbook features of malignancy, it has only recently become apparent that this occurs frequently among nonpalpable neoplasms, just those tumors that we must discover by screening. Radiologists must learn to search carefully, not only for characteristic tumor masses and clustered calcifications, but especially for the more subtle and indirect signs of malignancy.