Learning objectives
●Discuss advantages and disadvantages of Bi-RADS 3 classification●Review classification of BI-RADS 3 lesions on mammography, ultrasound, and MRI●Discuss prevalence and cancer yield of BI-RADS 3 lesions in clinical practice●Present case examples of Bi-RADS 3 lesions.
Background
Assessment category 3, probably benign, is reserved for specific imaging findings known to have > 0% but ≤ 2% likelihood of malignancy. It is NOT an ‘indeterminate’ category. When used properly, it reduces the number of benign biopsies while maintaining a high sensitivity. It is also cost-effective in comparison to immediate biopsy. Disadvantages are that it can cause confusion for interpreting physicians and referring physicians, may lead to patient anxiety, and decreased patient compliance with each subsequent diagnostic examination.
Imaging findings OR Procedure details
For mammography, it is necessary to complete diagnostic imaging evaluation before a probably benign assessment is assigned. A BI-RADS 3 assessment for mammograms is appropriate for a solitary circumscribed mass that appears solid at US, a focal asymmetry with no sonographic correlate, or a group of calcifications appearing punctate on magnification views. It is appropriate for these findings at baseline mammogram or without prior comparison but NOT for new findings on subsequent mammograms. A recent study evaluating the outcomes of BI-RADS 3 lesions on mammograms...
Conclusion
BI-RADS 3 is an intermediate category that appears to be evolving as we learn more about our imaging techniques for detecting breast cancer. While mammographic BI-RADS 3 categories in women over 60 have a likelihood of malignancy of greater than 2%, it may still be appropriate to closely follow-up these patients after a open discussion about risks and benefits. A few findings on ultrasound previously categorized as BI-RADS 3 can now be downgraded to BI-RADS 2 including clustered microcysts, complicated cysts, and multiple bilateral circumscribed...
References
CancerYieldand Patterns of Follow-up for BI-RADSCategory 3 after ScreeningMammographyRecall in theNationalMammographyDatabase.Berg WA, Berg JM, Sickles EA, Burnside ES, Zuley ML, Rosenberg RD, Lee CS.Radiology. 2020 Jul;296(1):32-41. doi: 10.1148/radiol.2020192641. Epub 2020 May 19.PMID:32427557
BI-RADSCategory 3 Comparison:ProbablyBenignCategory after Recall from Screening before and after Implementation of Digital Breast Tomosynthesis.McDonald ES, McCarthy AM, Weinstein SP, Schnall MD, Conant EF.Radiology. 2017 Dec;285(3):778-787. doi: 10.1148/radiol.2017162837. Epub 2017 Jul 17.PMID:28715278Free PMC article.
Probablybenignlesions at screening breast US in a population with elevated risk: prevalence and rate of malignancy in the ACRIN...