[Breast cancers: abnormalities visible on a single view]

This article reviews abnormal mammographic findings that do not meet the BIRADS description of masses or clusters of microcalcifications: abnormalities visible on a single view, asymmetrical densities and unusual patterns (transparent appearances, ductal patterns and diffuse abnormalities). It is important for radiologists to become familiar with unusual mammographic manifestations of malignant lesions to avoid misdiagnosis. Correlation with clinical abnormalities, optimal mammographic technique and comparison with previous films are useful and important for accurate interpretation of these difficult and/or unusual cases. Ultrasound, MRI and percutaneous biopsy are also useful in selected cases.