BI-RADS Classification for Management ofAbnormal MammogramsMargaret M. Eberl, MD, MPH, Chester H. Fox, MD, Stephen B. Edge, MD,Cathleen A. Carter, PhD, and Martin C. Mahoney, MD, PhD, FAAFP

The Breast Imaging Reporting and Data System (BI-RADS), developed by the American College of Radi-ology, provides a standardized classification for mammographic studies. This system demonstrates goodcorrelation with the likelihood of breast malignancy. The BI-RADS system can inform family physiciansabout key findings, identify appropriate follow-up and management and encourage the provision of ed-ucational and emotional support to patients. (J Am Board Fam Med 2006;19:1614.)

The Breast Imaging Reporting and Data System(BI-RADS) was developed in 1993 by the AmericanCollege of Radiology (ACR) to standardize mam-mographic reporting, to improve communication,to reduce confusion regarding mammographicndings, to aid research, and to facilitate outcomesmonitoring.1 According to the MammographyQuality Standards Act (MQSA) of 1997 [Final Rule62(208):55988], all mammograms in the UnitedStates must be reported using one of these assess-ment categories.1,2 Each mammographic studyshould be assigned a single assessment based on themost concerning ndings.1

The BI-RADS SystemTable 1 presents BI-RADS classications and man-agement recommendations as an evidence table.Classications are divided into an incomplete as-sessment (category 0) and completed assessments(categories 1, 2, 3, 4, 5, 6).1,3 Although there are 7assessment categories, only 4 outcomes are possi-ble: (1) additional imaging studies, (2) routine in-terval mammography, (3) short-term follow-up,and (4) biopsy.2 All categories reect the radiolo-gists level of suspicion for malignancy, and theseassessment categories have been shown to be cor-related with the likelihood of malignancy.2 Becauseeach BI-RADS category has only one specic rec-

ommendation, this system can both inform familyphysicians about ndings and direct appropriatefollow-up and management.4

The BI-RADS lexicon offers a number ofstrengths, including the application of a standard-ized common language to facilitate communicationbetween radiologists, referring physicians, and pa-tients. The system also claries the reporting ofmammography results and will support the com-pletion of quality improvement activities and clin-ical research.

The vast majority of screening mammogramsare classied as BI-RADS 1 and 2. Between 5% and9% of screening mammograms will require addi-tional follow-up or biopsy including up to 7% ofmammograms classied as BI-RADS category 3 aswell as the 2% of BI-RADS 4 or 5 mammo-grams.57 The positive predictive value of a biopsypositive for malignancy increases from 2% forBI-RADS category 3 mammograms to 23% to 30%for category 4 mammograms and to 95% for cate-gory 5 mammograms.8,9 Specic mammographicfeatures with the highest positive predictive valueof malignancy include masses with spiculated mar-gins and/or irregular shape, as well as calcicationswith linear morphology and/or segmental distribu-tion.10

Table 2 summarizes ndings from a population-based mammography registry in New Hampshireshowing the proportion of breast cancers observedby BI-RADS category. The rate of breast canceramong women with BI-RADS category 1, 2, or 3mammograms after 1 year of follow-up was approx-imately 1/1000 compared with 136/1000 amongthose with category 4 and 605/1000 with category5 mammograms.5

Submitted 21 July 2005; accepted 29 July 2005.From Roswell Park Cancer Institute (MME, SBE, CAC,

MCM), Buffalo, NY; and Department of Family Medicine(MME, CHF), State University of New York, Buffalo, NY.

Conict of interest: none declared.Corresponding author: Margaret M. Eberl, MD, MPH,

Roswell Park Cancer Institute, Elm and Carlton Streets,Buffalo, NY 14263 (Margaret.Eberl@RoswellPark.org).

http://www.jabfm.org Managing Mammograms Using BI-RADS 161

ConclusionGiven that BI-RADS can impact on patient care byminimizing both over-utilization and under-utili-zation of follow-up tests/procedures, it is criticalthat family physicians, and other clinicians provid-ing care to women, be familiar with the interpre-tation of and management strategy for each cate-gory.

Primary care physicians would benet from de-veloping mechanisms, in partnership with their col-laborating radiologists, to assure that all womenneeding further imaging (BI-RADS codes 0 and 3)

as well as women with suspicious mammograms(BI-RADS codes 4 and 5) undergo appropriate fol-low-up. This might include the creation of an ofceregistry to assure optimal management, as well asnecessary educational and emotional support.

Clinical Vignettes to Illustrate ClinicalManagement Using BI-RADS CodesCase 1A 48-year-old female had a screening mammogramshowing rounded densities with possible irregularborders amid dense breast tissue bilaterally.

Table 1. Evidence Table for Clinical Management Recommendations for Mammograms by Breast ImagingReporting and Data System (BI-RADS) Category

BI-RADS Clinical ManagementRecommendation(s)

Strength ofRecommendation References

Comments onReferencesCategory Assessment

0 Assessment incomplete Need to review priorstudies and/or completeadditional imaging

A 3 All or none study; consensusguidelines

1 Negative Continue routine screening A 3, 8 Consensus guidelines;validated clinical decisiontool

2 Benign nding Continue routine screening A 3, 8 Consensus guidelines;validated clinical decisiontool

3 Probably benign nding Short-term follow-upmammogram at 6months, then every 6 to12 months for 1 to 2years

B 3, 6, 8,1015

Consensus guidelines; cohortstudies; large case series;validated decision tool; lesspatient stress; loweredcosts with surveillance

4 Suspicious abnormality Perform biopsy, preferablyneedle biopsy

A 3, 810 All or none study; validatedclinical decision tool

5 Highly suspicious ofmalignancy; appropriateaction should be taken.

Biopsy and treatment, asnecessary.

A 3, 810 All or none study; validatedclinical decision tool

6 Known biopsy-provenmalignancy, treatmentpending

Assure that treatment iscompleted

Table 2. Mammography Assessment and Breast Cancers Detected in the New Hampshire Mammography Registry,11/96 to 10/97, by Breast Imaging Reporting and Data System (BI-RADS) category

BI-RADSCategory

Baseline Mammography*Breast Cancers Detected

Rate/1000Anticipated Rate of

Malignancy Following BiopsyNumber Percentage

1 37,995 80.65% 0.7 2 4,930 10.46% 1.2 3 3,345 7.10% 8.1 2%68

4 766 1.63% 135.8 23%34%1215

5 76 0.16% 605.3 95%1,4,1215

Total 47,112 100.00%

* Data derived from Poplack et. al.5

Categories 1 and 2 are considered to be negative test results.

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Radiologic Interpretation: BI-RADS 0 (additional imagingneeded)One week later, she had spot compression viewsthat showed the nodules to be regular and sharplydened. Ultrasound examination revealed cysts. Fi-nal classication as BI-RADS 2 (benign nding).Patient should continue with routine breast cancerscreening.

Case 2A 57-year-old female completed a screening mam-mogram showing calcications in the right breast.These lesions were conned to the upper outerquadrant but were scattered and round on magni-cation views. The only prior mammogram wasfrom 4 years ago, was of poor quality, and onlyshowed a few scattered calcications.

Radiologic Interpretation: BI-RADS 3 (probably benign)Despite the lack of a recent prior comparison mam-mogram, the current calcications were felt to be oflow suspicion. During a discussion the patient wasinformed that the calcications were felt to be oflow suspicion. A repeat mammography was recom-mended in 6 months. Follow-up mammogram at 6months and subsequently at 1 year showed nochange in these calcications.

Case 3A 53-year-old female had a screening mammogramthat showed linear calcications clustered tightly inthe upper outer quadrant of the right breast. Mag-nication views conrmed these were clustered andthat there was no associated mass. The calcica-tions were not present on a mammogram obtained12 months earlier.

Radiologic Interpretation: BI-RADS 4 (suspiciousabnormality)Results were reviewed with the patient and biopsywas recommended. Vacuum-assisted needle biopsy(Mammotome) was performed using mammo-graphic stereotactic localization. Pathology showedatypical ductal hyperplasia. Subsequent excisionalbiopsy conrmed the absence of malignancy.

Case 4A 62-year-old female completed a screening mam-mogram showing a 1-cm spiculated mass with as-

sociated calcications lateral to the left nipple area.This lesion was not present on prior mammograms.

Radiologic Interpretation: BI-RADS 5 (highly suspicious ofmalignancy)Results were reviewed with the patient, and needlebiopsy was recommended. Vacuum-assisted needlebiopsy (Mammotome) was performed using mam-mographic stereotactic localization. Pathologyshowed inltrating ductal carcinoma, grade II.

Patient Education

What is BI-RADS? BI-RADS is a system thatwas developed by radiologists for reportingmammogram results using a common language.The radiologist assigns a single digit BI-RADSscore (ranging from 0 to 5) when the report ofyour mammogram is created.

What does BI-RADS 0 mean? BI-RADS 0identies a mammogram study that is not yetcomplete. You need to make sure that furtherevaluation is completed, perhaps extra mammog-raphy views or an ultrasound. Further informa-tion is needed to make a nal assessment (codes 1to 5).

What does BI-RADS 1 mean? BI-RADS 1means that the mammogram was negative (ie, nocancer) and that you should continue your rou-tine screening.

What does BI-RADS 2 mean? BI-RADS 2 alsomeans that your mammogram was normal (ie, nocancer), but other ndings (eg, cysts) are de-scribed in the report. You should continue yourroutine screening.

What does BI-RADS 3 mean? BI-RADS 3means that your mammogram is probably normalbut a repeat mammogram should be completedin 6 months. The chance of breast cancer isapproximately 2% in this category. You shouldmake sure that these follow-up mammograms arecompleted as requested.

What does BI-RADS 4 mean? BI-RADS 4means that the ndings on your mammogram aresuspicious and that there is approximately a 23%to 34% chance that this is breast cancer. You willneed a biopsy to get a small tissue sample to makea diagnosis. Talk to your doctors about any ques-tions.

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What is a biopsy? Biopsy is done to obtain apiece of the breast tissue to determine whetherthere is cancer. The biopsy may be done using aneedle technique (a needle biopsy) or may re-quire a surgical operation (a surgical biopsy).When a needle biopsy is an option, it is usuallypreferred.

What does BI-RADS 5 mean? BI-RADS 5means that your mammogram results are highlysuspicious with a 95% chance of breast cancer.You will need to have a biopsy for diagnosis. Talkto your doctors about what course of action totake.

What does BI-RADS 6 mean? BI-RADS 6 meansthat you have already been diagnosed with breastcancer. Discuss your treatment plan with yourdoctors.

Why do I need to know my BI-RADS score?Knowing your BI-RADS number can help tomake sure that you get proper follow-up afteryour mammogram. It is a good thing for you toknow that score so you can keep track, along withyour physician, of what you need to do and ac-tively participate in your medical care.

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3. Singletary E, Anderson B, Bevers T, Borgen P, BuysS, Daly M. National comprehensive cancer network:clinical practice guidelines in oncology, breast cancerscreening and diagnosis guidelines, v. 1.2003. 08/20/02. Available from: http://www.nccn.org/physician_gls/f_guidelines.html. Accessed March 1, 2004.

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8. Lacquement MA, Mitchell D, Hollingsworth AB.Positive predictive value of the Breast Imaging Re-porting and Data System. J Am Coll Surg 1999;189:3440.

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13. Lindfors KK, OConnor J, Acredolo CR, Liston SE.Short-interval follow-up mammography versus im-mediate core biopsy of benign breast lesions: assess-ment of patient stress. AJR Am J Roentgenol 1998;171:558.

14. Brenner RJ, Sickles EA. Surveillance mammographyand stereotactic core breast biopsy for probably be-nign lesions: a cost comparison analysis. Acad Radiol1997;4:41925.

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