Assessment and Management of Challenging BI-RADS Category 3 Mammographic Lesions

The Impact of Mammographic, Radiologist, and Patient Factors on the Likelihood of Probably Benign (BI-RADS 3) Assessment at Diagnostic Mammography

OBJECTIVE

To evaluate the association of mammographic, radiologist, and patient factors on BI-RADS 3 assessment at diagnostic mammography in patients recalled from screening mammography.

METHODS

This Institutional Review Board-approved retrospective study of consecutive unique diagnostic mammography examinations in asymptomatic patients recalled from screening mammography March 5, 2014, to December 31, 2019, was conducted in a single large United States health care institution. Mammographic features (mass, calcification, distortion, asymmetry), breast density, prior examination, and BI-RADS assessment were extracted from reports by natural language processing. Patient age, race, and ethnicity were extracted from the electronic health record. Radiologist years in practice, recall rate, and number of interpreted diagnostic mammograms were calculated. A mixed effect logistic regression model evaluated factors associated with likelihood of BI-RADS 3 compared with other BI-RADS assessments.

RESULTS

A total of 12 080 diagnostic mammography examinations were performed during the study period, yielding 2010 (16.6%) BI-RADS 3 and 10 070 (83.4%) other BI-RADS assessments. Asymmetry (odds ratio [OR] = 6.49, P <.001) and calcification (OR = 5.59, P <.001) were associated with increased likelihood of BI-RADS 3 assessment; distortion (OR = 0.20, P <.001), dense breast parenchyma (OR = 0.82, P <.001), prior examination (OR = 0.63, P = .01), and increasing patient age (OR = 0.99, P <.001) were associated with decreased likelihood. Mass, patient race or ethnicity, and radiologist factors were not significantly associated with BI-RADS 3 assessment. Malignancy rate for BI-RADS 3 lesions was 1.6%.

CONCLUSION

Asymmetry and calcifications had an increased likelihood of BI-RADS 3 assessment at diagnostic evaluation with low likelihood of malignancy, while radiologist features had no association.

The Postoperative Breast: Imaging Findings and Diagnostic Pitfalls After Breast-Conserving Surgery and Oncoplastic Breast Surgery

Breast surgery is the cornerstone of treatment for early breast cancer. Historically, mastectomy and conventional breast-conserving surgery (BCS) were the main surgical techniques for treatment. Now, oncoplastic breast surgery (OBS), introduced in the 1990s, allows for a combination of BCS and reconstructive surgery to excise the cancer while preserving or enhancing the contour of the breast, leading to improved aesthetic results. Although imaging after conventional lumpectomy demonstrates typical postsurgical changes with known evolution patterns over time, OBS procedures show postsurgical changes/fat necrosis in locations other than the lumpectomy site. The purpose of this article is to familiarize radiologists with various types of surgical techniques for removal of breast cancer and to distinguish benign postoperative imaging findings from suspicious findings that warrant further work-up.

Improving the malignancy prediction of breast cancer based on the integration of radiomics features from dual-view mammography and clinical parameters

Radiomics has been a promising imaging biomarker for many malignant diseases. We developed a novel radiomics strategy that incorporating radiomics features extracted from dual-view mammograms and clinical parameters for identifying benign and malignant breast lesions, and validated whether the radiomics assessment could improve the accurate diagnosis of breast cancer. A total of 380 patients (mean age, 52 ± 7 years) with 621 breast lesions utilizing mammograms on craniocaudal (CC) and mediolateral oblique (MLO) views were randomly allocated into the training (n = 486) and testing (n = 135) sets in this retrospective study. A total of 1184 and 2368 radiomics features were extracted from single-position region of interest (ROI) and position-paired ROI, separately. Clinical parameters were then combined for better prediction. Recursive feature elimination and least absolute shrinkage and selection operator methods were applied to select optimal predictive features. Random forest was used to conduct the predictive model. Intraclass correlation coefficient test was used to assess repeatability and reproducibility of features. After preprocessing, 467 radiomics features and clinical parameters remained in the single-view and dual-view models. The performance and significance of models were quantified by the area under the curve (AUC), sensitivity, specificity, and accuracy. The correlation analysis between variables was evaluated using the correlation ratio and Pearson correlation coefficient. The model using a combination of dual-view radiomics and clinical parameters achieved a favorable performance (AUC: 0.804, 95% CI: 0.668-0.916), outperformed single-view model and model without clinical parameters. Incorporating with radiomics features of dual-view (CC&MLO) mammogram, age, breast density, and type of suspicious lesions can provide a noninvasive approach to evaluate the malignancy of breast lesions and facilitate clinical decision-making.

Cracking open the eristic rhetoric of contralateral prophylactic mastectomy research or why surgeons should not be so certain about this controversial breast cancer treatment

Contralateral prophylactic mastectomy (CPM) is a controversial breast cancer treatment in which both breasts are removed when only one is affected by cancer. Rates of CPM have been rising since the late 1990s, despite surgeons' strong agreement that the procedure should not be performed for average-risk women. This essay analyses that agreement as it is demonstrated in the surgical literature on CPM, arguing that it forms a 'rhetoric of certainty' built on the stark epistemological divide between objective and subjective forms of knowledge that operates in some areas of medicine. Further, the essay argues that this rhetoric of certainty has the potential to function as a kind of eristic rhetoric in which the right conclusion is known prior to any rhetorical exchange. As a way to 'crack open' this certainty, the essay compares the rhetoric of the surgical literature on CPM to the rhetoric of uncertainty in the radiological literature on breast cancer screening for women with a personal history of the disease. The goal of this comparison is not to suggest surgeons should support all choices for CPM. Rather, the aim is to demonstrate that choices against the procedure are not as straightforward as the surgical literature indicates and that the uncertainty affecting women's preferences for CPM is not solely the result of patient misunderstanding and/or emotional instability.

Outcome of Imaging and Biopsy of BI-RADS Category 3 Lesions: Follow-Up Compliance, Biopsy, and Malignancy Rates in a Large Patient Cohort

OBJECTIVES

To identify biopsy rates and indications for BI-RADS 3 lesions in a large cohort of patients and compare with follow-up compliance and malignancy outcomes.

METHODS

We retrospectively reviewed all BI-RADS category-3 lesions seen on mammography and/or ultrasound between 2013 and 2015. Patient age, lesion size, follow-up rates at 6-, 12-, and 24-months were collected. Biopsy timing, indication, and outcomes (malignant vs benign) were recorded using at least 2-year follow-up or biopsy pathology as endpoint.

RESULTS

Of 2319 BI-RADS 3 lesions in 2075 women analyzed, biopsy was performed in 173 (7.5%). Most biopsies were performed upfront (99, 57.2%), followed by at 6 (44, 25.4%), 12 (21, 12.1%), and 24-month follow-up (9, 5.2%; P < .001). Palpable (P < .001) and larger (median 1.4 vs 1.0 cm, P < .001) lesions in women <40 years (15.2% vs 4.8%, P < .001) were more likely to undergo biopsy. Most biopsies were prompted by patient/physician desire (64.5%, P < .001). Of 783 lesions with available endpoint, 5 (0.6%) were cancer. All cancers were identified either at presentation (in 0-5 months, n = 1) or 6-month follow-up (in 5-9 months, n = 4) with biopsy prompted by either morphology change (n = 3) or lesion growth (n = 2). Of the 1855 lesions which were expected for follow up, only 310 (16.7%) underwent all follow-ups, while 482 (26.1%) had two, 489 (26.5%) one, and 565 (30.6%) had no follow-up.

CONCLUSIONS

In our cohort, BI-RADS category 3 lesions had significantly higher biopsy rates compared with the small malignancy rate, all of which were identified at baseline or first follow-up. Overall patient follow-up compliance low. Imaging follow-up, especially at first 6-month time point, should be encouraged in BI-RADS 3 lesions, instead of upfront biopsies.

A Single-Center Audit of BI-RADS 3 Assessment Category Utilization in Mammography and Breast Ultrasound

Purpose: To evaluate outcomes of breast lesions assessed at our institution as probably benign (Breast Imaging Reporting and Data System [BI-RADS] category 3) with an expected malignancy rate of less than or equal to 2 %. Methods: Average-risk women with a BI-RADS 3 assessment following mammographic and/or ultrasound evaluation at our institution between January 1 and December 31, 2017 were included. Cancer yield was calculated within 90 days and at 6-month intervals up to 36 months. Results: Among 517 women (median age, 52 years; range, 13-89 years) with a BI-RADS 3 assessment, 349 (67.5 %) underwent biopsy or completed follow-up imaging up to 36 months. One hundred and 68 (32.5 %) were lost to follow-up. Thirty of 349 (8.6 %) had their imaging upgraded and underwent biopsy, yielding six cancers (cancer yield, 6 of 349 women [1.7 %]). Among 569 lesions assessed as BI-RADS 3, 92 (16.2 %) were characterized by morphologic features other than those validated as probably benign in prospective clinical studies. Fifty three of 517 women (10.3 %) had follow-up beyond 24 months, and 24 (4.6 %) had follow-up beyond 36 months. Conclusion: Overall utilization of the BI-RADS 3 assessment category at our institution is appropriate with a 1.7 % cancer yield. However, the rate of loss to follow-up, percentage of non-validated findings assessed as probably benign, and redundancy in follow-up protocols are too high, and warrant intervention. A patient handout explaining the BI-RADS 3 assessment category and automatic scheduling of follow-up studies have been implemented at our center to address loss to follow-up.

Does MRI have added value in ultrasound-detected BIRADS-3 breast masses in candidates for assisted reproductive therapy?

Background

Ultrasound-detected breast lesions with probably benign features are a great challenge for clinicians, especially in breasts with dense composition. We aimed to investigate the finding of two radiologic modalities on these lesions.

Methods

This retrospective cross-sectional study recruited patients including (1) candidates of assisted reproductive therapy (ART), (2) patients with prior high-risk lesions, and (3) the "suspected" BIRADS-3 masses referring to masses that US BIRADS-3 was not compatible with the clinical breast exam. The degree of agreement in diagnosing BIRADS-3 lesions between two modalities of magnetic resonance imaging (MRI) and ultrasonography (US), and comparison of the lesions in US and MRI were the study variables.

Results

A total number of 123 lesions in 67 patients with a median age of 38 (IQR: 11, range: 17-67). In the examination by MRI, 107 (87.0 %) lesions were BIRADS-3 indicating the agreement level between these two modalities. The median size of the lesions in US was 9 mm (IQR: 5, range: 3-43) and 9 mm (IQR: 10, range: 4-46) in MRI. The measured size of the lesions between the two modalities was highly correlated (Spearman correlation coefficient: 0.889, P-value < 0.001). MRI evaluation revealed two cases of deep lesions which were missed in the US imaging.

Conclusions

This study found relatively high agreement values between US and MRI in detecting BIRADS-3 breast lesions in candidates for ART or patients with prior high-risk lesions. Also, MRI could downgrade about one-tenth of the cases to a lower BIRADS level and resolved the need for closer follow-up.

A rare phenotype of breast hydatid cyst causing misdiagnosis and unnecessary intervention: a case report

Hydatid cyst (cystic echinococcosis) is a chronic parasitic infection by the larval stage of the cestode that is called Echinococcus granulosus (E. granulosus) resulting in the development of cystic lesions in animals and humans. In this report, we describe a rare phenotype of hydatid cyst in the breast of a 23-year-old female presented with breast mass in the left upper outer quadrant for 3 months with palpable left axillary lymph nodes. Both US and mammography provided a picture of complex suspicious cystosolid lesion with amorphous micro-calcification (BIRAD-4A). Surgical consultation was performed and Tru-Cut biopsy was recommended. Histopathology results revealed multiple viable protoscolices of E. granulosus and suggested the final diagnosis of breast hydatid cyst. The patient returned with ruptured and infected hydatid cyst of the breast and started treatment with Albendazole 400 mg twice daily in addition to antibiotics. Following-up after two months of Albendazole treatment showed a dramatic shrinkage in the size of the cystic lesion. In conclusion, hydatid cyst should be considered as a differential diagnosis of any cystic or cystosolid lesion in the breast and any organ in the body from head to toe apart from the hair and nails. Radiologists should be aware to the benign lesions that may mimic breast cancer to avoid misdiagnosis and unnecessary invasive procedures and consequent complications.

Current Status and Future of BI-RADS in Multimodality Imaging, From the AJR Special Series on Radiology Reporting and Data Systems

BI-RADS is a communication and data tracking system that has evolved since its inception as a brief mammography lexicon and reporting guide into a robust structured reporting platform and comprehensive quality assurance tool for mammography, ultrasound, and MRI. Consistent and appropriate use of the BI-RADS lexicon terminology and assessment categories effectively communicates findings, estimates the risk of malignancy, and provides management recommendations to patients and referring clinicians. The impact of BI-RADS currently extends internationally through six language translations. A condensed version has been proposed to facilitate a phased implementation of BI-RADS in resource-constrained regions. The primary advance of the 5th edition of BI-RADS is harmonization of the lexicon terms across mammography, ultrasound, and MRI. Harmonization has also been achieved across these modalities for the reporting structure, assessment categories, management recommendations, and data tracking system. Areas for improvement relate to certain common findings that lack lexicon descriptors and a need for further clarification of proper use of category 3. BI-RADS is anticipated to continue to evolve for application to a range of emerging breast imaging modalities.

Follow-Up Intervals for Breast Imaging Reporting and Data System Category 3 Lesions on Screening Ultrasound in Screening and Tertiary Referral Centers

Objective

To assess the appropriate follow-up interval, and rate and timepoint of cancer detection in women with Breast Imaging Reporting and Data System (BI-RADS) 3 lesions on screening ultrasonography (US) according to the type of institution.

Materials and Methods

A total of 1451 asymptomatic women who had negative or benign findings on screening mammogram, BI-RADS 3 assessment on screening US, and at least 6 months of follow-up were included. The median follow-up interval was 30.8 months (range, 6.8–52.9 months). The cancer detection rate, cancer detection timepoint, risk factors, and clinicopathological characteristics were compared between the screening and tertiary centers. Nominal variables were compared using the chi-square or Fisher's exact test and continuous variables were compared using the independent t test or Mann-Whitney U test.

Results

In 1451 women, 19 cancers (1.3%) were detected; two (0.1%) were diagnosed at 6 months and 17 (1.2%) were diagnosed after 12.3 months. The malignancy rates were both 1.3% in the screening (9 of 699) and tertiary (10 of 752) centers. In the screening center, all nine cancers were invasive cancers and diagnosed after 12.3 months. In the tertiary center, two were ductal carcinomas in situ and eight were invasive cancers. Two of the invasive cancers were diagnosed at 6 months and the remaining eight cancers newly developed after 13.1 months.

Conclusion

One-year follow-up rather than 6-month follow-up may be suitable for BI-RADS 3 lesions on screening US found in screening centers. However, more caution is needed regarding similar findings in tertiary centers where 6-month follow-up may be more appropriate.

Variability in Individual Radiologist BI-RADS 3 Usage at a Large Academic Center: What's the Cause and What Should We Do About It?

RATIONALE AND OBJECTIVES

Although the breast imaging reporting and data system (BI-RADS) lists specific criteria for designating a lesion as BI-RADS category 3 (probably benign), there are no target benchmarks for BI-RADS 3 usage rates. This study investigates the variability of BI-RADS 3 rates among a group of academic breast imagers, with the goal of defining more precise utilization.

MATERIALS AND METHODS

We retrospectively reviewed all diagnostic mammograms performed between July 1, 2013 and August 8, 2017 at our academic institution. The percentage of diagnostic mammograms given a BI-RADS 3 assessment was compared between radiologists using the Chi-square test. We then evaluated for correlation between BI-RADS 3 rate and individual clinical metrics (eg, radiologist experience, cancer detection rate [CDR] and recall rate) using univariate linear regression.

RESULTS

The study included 13 breast imagers and 24,051 diagnostic breast examinations. There was significant variability in BI-RADS 3 rates between radiologists, ranging from 8.0% to 19.3% (p < 0.001). Increased BI-RADS 3 rates negatively correlated with BI-RADS 1 or 2 rate (p < 0.001) and positively correlated with recall rate (p = 0.03). There was no association between BI-RADS 3 rate and the radiologist's level of experience, BI-RADS 4 or 5 rate, or CDR.

CONCLUSION

We found significant variability in BI-RADS 3 usage, which seems to be used in place of BI-RADS 1 or 2 findings rather than to avoid biopsy recommendation. BI-RADS 3 rates also directly correlated with recall rate, suggesting a greater degree of uncertainty among specific radiologists. Importantly, increased usage of BI-RADS 3 did not correlate with provider experience or improved CDR.

Calcifications at Digital Breast Tomosynthesis: Imaging Features and Biopsy Techniques

Full-field digital mammography (FFDM), the standard of care for breast cancer screening, has some limitations. With the advent of digital breast tomosynthesis (DBT), improvements including decreased recall rates and increased cancer detection rates have been observed. The quasi-three-dimensional capability of DBT reduces breast tissue overlap, a significant limitation of FFDM. However, early studies demonstrate that a few cancers detected at FFDM may not be diagnosed at DBT-only screening, and lesions with calcifications as the dominant feature may look less suspicious at DBT or not be visible at all. These findings support the use of combined FFDM and DBT protocols to optimize screening performance. However, this combination would approximately double the patient's radiation exposure. The development of computer algorithms that generate two-dimensional synthesized mammography (SM) views from DBT has improved calcification conspicuity and sensitivity. Therefore, SM may substitute for FFDM in screening protocols, reducing radiation exposure. DBT plus SM demonstrates significantly better performance than that of FFDM alone, although there are reports of missed malignant calcifications. Thus, some centers continue to perform FFDM with DBT. Use of DBT in breast imaging has also necessitated the development of DBT-guided biopsy. DBT-guided biopsy may have a higher success rate than that of stereotactic biopsy, with a shorter procedure time. While DBT brings substantial improvements to breast cancer imaging, it is important to be aware of its strengths and limitations regarding detection of calcifications. This article reviews the imaging appearance of breast calcifications at DBT, discusses calcification biopsy techniques, and provides an overview of the current literature. Online supplemental material is available for this article. ^©RSNA, 2019 An earlier incorrect version of this article appeared online. This article was corrected on February 13, 2019.

BI-RADS 3: Current and Future Use of Probably Benign

PURPOSE OF REVIEW

Probably benign (BI-RADS 3) causes confusion for interpreting physicians and referring physicians and can induce significant patient anxiety. The best uses and evidence for using this assessment category in mammography, breast ultrasound, and breast MRI will be reviewed; the reader will have a better understanding of how and when to use BI-RADS 3.

RECENT FINDINGS

Interobserver variability in the use of BI-RADS 3 has been documented. The 5th edition of the BI-RADS atlas details the appropriate use of BI-RADS 3 for diagnostic mammography, ultrasound, and MRI, and discourages its use in screening mammography. Data mining, elastography, and diffusion weighted MRI have been evaluated to maximize the accuracy of BI-RADS 3.

SUMMARY

BI-RADS 3 is an evolving assessment category. When used properly, it reduces the number of benign biopsies while allowing the breast imager to maintain a high sensitivity for the detection of early stage breast cancer.