How accurate is an ultrasound for breast cancer?

Very: When ultrasounds are used to evaluate a palpable lump or a mammographic abnormality, a directed ultrasound can very accurately differentiate a benign tumor from a malignant one. Nevertheless, it is best to not rely exclusively on an ultrasound and to proceed to tissue diagnosis via biopsy, especially for women over age 40.

Very accurate: Breast cancer usually makes or presents as a mass or tumor or a lump. Ultrasound is very accurate in such cases and may be used to do a biopsy.

It depends: on what specifically you are asking. Ultrasound can be used for screening asymptomatic women, it can be used in a diagnostic setting to evaluate lumps or abnormalities detected on other imaging, or for biopsy guidance. In the screening setting, it is 60-80 percent sensitive for detecting cancer.