Breast imaging-reporting and data system (BI-RADS) assessment category 5
BI-RADS 5 lesions under the BI-RADS (breast imaging reporting and data system) refer to breast lesions that are highly suspicious for malignancy, requiring appropriate action to be taken (i.e. biopsy and management as appropriate). BI-RADS 5 lesions have the characteristic morphology of breast cancer with a ≥95% chance of being malignant1.
The implication of a BI-RADS 5 finding, in contrast to BI-RADS 4, is that if the histology is benign, it should be considered discordant with imaging findings, and lesion excision is still advised.
Radiographic features
Mammography
A BI-RADS 5 lesion has the typical imaging features of breast malignancy. On a mammogram, any two of the following features are demonstrated:
spiculated or irregular mass
high density
fine linear or linear branching segmental calcifications
Nipple retraction, skin thickening and evidence of interval growth, if present, would support the diagnosis.
