DCIS is most often discovered during a mammogram used to screen for breast cancer. If your mammogram shows suspicious areas such as bright white specks (microcalcifications) that are in a cluster and have irregular shapes or sizes, your radiologist likely will recommend additional breast imaging.
You may have a diagnostic mammogram, which takes views at higher magnification from more angles. This examination evaluates both breasts and takes a closer look at the microcalcifications to be able to determine whether they are a cause for concern.
If the area of concern needs further evaluation, the next step may be an ultrasound and a breast biopsy.
Removing breast tissue samples for testing
During a core needle biopsy, a radiologist or surgeon uses a hollow needle to remove tissue samples from the suspicious area, sometimes guided by ultrasound (ultrasound-guided breast biopsy) or by X-ray (stereotactic breast biopsy). The tissue samples are sent to a lab for analysis.
In a lab, a doctor who specializes in analyzing blood and body tissue (pathologist) will examine the samples to determine whether abnormal cells are present and if so, how aggressive those abnormal cells appear to be.