Detection of early invasive breast cancer is important, as patient survival is high when the cancer is 2 cm or smaller. Invasive breast cancers typically manifest mammographically as focal asymmetries or masses. Strategies for detecting focal asymmetries and masses on screening mammograms include side-by-side comparison, looking for parenchymal contour deformity, close inspection of the retromammary fat, identifying the presence of associated findings, and comparison with prior mammograms. Focal asymmetries are often normal but are concerning when there is distortion of the normal breast architecture. Masses and focal asymmetries are best evaluated in the diagnostic setting by using spot compression and true lateral views and, frequently, ultrasonography. Management of a lesion depends on the worst imaging feature. Indications for an assessment of probably benign findings are very specific but are often misapplied. This review for residents provides a practical approach to the detection and management of breast masses and focal asymmetries.
(c) RSNA, 2008.