Tomosynthesis-Guided Vacuum-Assisted Breast Biopsy of Architectural Distortion Without a Sonographic Correlate: A Retrospective Review

Fibrocystic Change

Fibrocystic changes are commonly seen in clinically symptomatic patients and during imaging workup of screening-detected findings. The term "fibrocystic changes" encompasses a broad spectrum of specific benign pathologic entities. Recognition of classically benign findings of fibrocystic changes, including cysts and layering calcifications, can prevent unnecessary follow-ups and biopsies. Imaging findings such as solid masses, nonlayering calcifications, and architectural distortion may require core needle biopsy for diagnosis. In these cases, understanding the varied appearances of fibrocystic change aids determination of radiologic-pathologic concordance. Management of fibrocystic change is typically conservative.

Clinical benefits of tomosynthesis-guided vacuum assisted breast biopsy: a comparison with stereotactic vacuum assisted biopsy

BACKGROUND

Tomosynthesis-guided vacuum assisted breast biopsy (3D-VAB) has been used increasingly. The aim of our study is to compare the clinical effectiveness of 3D-VAB and stereotactic vacuum assisted biopsy (2D-VAB) on the number of tissue cores containing targeted calcifications and on the procedure time.

METHODS

Consecutive 87 women who underwent biopsy at our hospital from April 2020 to March 2022 for calcifications mammographically suspicious of malignancy were included in this study: 57 patients with 3D-VAB and 30 patients with 2D-VAB.

RESULTS

Grouped or clustered calcified lesions were found in 39 and 21 patients among the 3D-VAB group and the 2D-VAB group, respectively. The mean number of tissue cores per biopsy containing targeted calcifications from the grouped or clustered calcified lesions was 3 and 2.3 specimens for the 3D-VAB group and for the 2D-VAB group, respectively. The mean procedure time for grouped or clustered calcifications was significantly shorter in the 3D-VAB group than in the 2D-VAB group (16.5 min vs. 27.4 min, P < 0.01). Comparing the procedure time between 3D-VAB and 2D-VAB based on calcification category, 3D-VAB had significantly shorter procedure time than 2D-VAB for both category 3 and category 4 calcification. For all patients, the mean procedure time was 18.1 min for the 3D-VAB group and 27.7 min for the 2D-VAB, thus being significantly shorter with 3D-VAB than 2D-VAB (P < 0.01).

CONCLUSION

Our study demonstrated that the clinical effectiveness of 3D-VAB is superior to that of 2D-VAB and that the significant reduction in examination time with 3D-VAB is expected to benefit patients.

Suspicious Ultrasound-Occult Non-Calcified Mammographic Masses, Asymmetries, and Architectural Distortions Are Moderate Probability for Malignancy

Suspicious non-calcified mammographic findings have not been evaluated with modern mammographic technique, and the purpose of this work is to compare the likelihood of malignancy for those findings. To do this, 5018 consecutive mammographically guided biopsies performed during 2016-2019 at a large metropolitan, community-based hospital system were retrospectively reviewed. In total, 4396 were excluded for targeting calcifications, insufficient follow-up, or missing data. Thirty-seven of 126 masses (29.4%) were malignant, 44 of 194 asymmetries (22.7%) were malignant, and 77 of 302 architectural distortions (AD, 25.5%) were malignant. The combined likelihood of malignancy was 25.4%. Older age was associated with a higher likelihood of malignancy for each imaging finding type (all p ≤ 0.006), and a possible ultrasound correlation was associated with a higher likelihood of malignancy when all findings were considered together (p = 0.012). Two-view asymmetries were more frequently malignant than one-view asymmetries (p = 0.03). There were two false-negative biopsies (98.7% sensitivity and 100% specificity). In conclusion, the 25.4% likelihood of malignancy confirms the recommendation for biopsy of suspicious, ultrasound-occult, mammographic findings. Mammographically guided biopsies were highly sensitive and specific in this study. Older patient age and a possible ultrasound correlation should raise concern given the increased likelihood of malignancy in those scenarios.

Practical Challenges of DBT-Guided VABB: Harms and Benefits, from Literature to Clinical Experience

Vacuum-assisted breast biopsy (VABB) guided by digital breast tomosynthesis (DBT) represents one of the best instruments to obtain a histological diagnosis of suspicious lesions with no ultrasound correlation or those which are visible only on DBT. After a review of the literature, we retrospectively analyzed the DBT-guided VABBs performed from 2019 to 2022 at our department. Descriptive statistics, Pearson's correlation and χ2 test were used to compare distributions of age, breast density (BD) and early performance measures including histopathology. We used kappa statistics to evaluate the agreement between histological assessment and diagnosis. Finally, we compared our experience to the literature to provide indications for clinical practice. We included 85 women aged 41-84 years old. We identified 37 breast cancers (BC), 26 stage 0 and 11 stage IA. 67.5% of BC was diagnosed in women with high BD. The agreement between VABB and surgery was 0.92 (k value, 95% CI: 0.76-1.08). We found a statistically significant inverse correlation between age and BD. The post-procedural clip was correctly positioned in 88.2%. The post-procedural hematoma rate was 14.1%. No infection or hemorrhage were recorded. When executed correctly, DBT-guided VABB represents a safe and minimally invasive technique with high histopathological concordance, for detecting nonpalpable lesions without ultrasound correlation.

Comparison of prone and upright, stereotactic, and tomosynthesis-guided biopsies with secondary analysis of ultrasound-occult architectural distortions

OBJECTIVES

Compare prone and upright, stereotactic, and tomosynthesis-guided vacuum-assisted breast biopsies (prone DM-VABB, prone DBT-VABB, upright DM-VABB, and upright DBT-VABB) in a community-practice setting and review outcomes of ultrasound-occult architectural distortions (AD).

METHODS

Consecutive biopsies performed at two community-based breast centers from 2016 to 2019 were retrospectively reviewed. Technical details of each procedure and patient outcomes were recorded. Separate analyses were performed for ultrasound-occult ADs. Two sample t-tests and Fisher's exact test facilitated comparisons.

RESULTS

A total of 1133 patients underwent 369 prone DM-VABB, 324 prone DBT-VABB, 437 upright DM-VABB, and 123 upright DBT-VABB with 99.2%, 100%, 99.3%, and 99.2% success, respectively (p-values > 0.25). Mean lesion targeting times were greater for prone biopsy (minutes: 6.94 prone DM-VABB, 8.54 prone DBT-VABB, 5.52 upright DM-VABB, and 5.51 upright DBT-VABB; p-values < 0.001), yielding longer total prone procedure times for prone biopsy (p < 0.001). Compared to DM-VABB, DBT-VABB used fewer exposures (p < 0.001) and more commonly targeted AD, asymmetries, or masses (p < 0.001). Malignancy rates were similar between procedures: prone DM-VABB 22.4%, prone DBT-VABB 21.9%, upright DM-VABB 22.8%, and upright DBT-VABB 17.2% (p-values > 0.19). One hundred forty of the 1133 patients underwent 145 biopsies for ultrasound-occult AD (143 DBT-VABB and 2 DM-VABB). Biopsy yielded 27 malignancies and 47 high-risk lesions (74 of 145, 51%). Malignancy rate was 20.7% after surgical upgrade of one benign-discordant and two high-risk lesions.

CONCLUSIONS

All biopsy procedure types were extremely successful. The 20.7% malignancy rate for ultrasound-occult AD confirms a management recommendation for tissue diagnosis. Upright biopsy was faster than prone biopsy, and DBT-VABB used fewer exposures than DM-VABB.

CLINICAL RELEVANCE

Our results highlight important differences between prone DM-VABB, prone DBT-VABB, upright DM-VABB, and upright DBT-VABB. Moreover, the high likelihood of malignancy for ultrasound-occult AD will provide confidence in recommending tissue diagnosis in lieu of observation or clinical follow-up.

KEY POINTS

• Upright and prone stereotactic and tomosynthesis-guided breast biopsies were safe and effective in the community-practice setting. • The malignancy rate for ultrasound-occult architectural distortion of 20.7% confirms the management recommendation for biopsy. • Upright procedures were faster than prone procedures, and tomosynthesis-guided biopsy used fewer exposures than stereotactic biopsy.

Pathologic Outcomes in Single Versus Multiple Areas of Architectural Distortion on Digital Breast Tomosynthesis

BACKGROUND. Digital breast tomosynthesis (DBT) has led to increased detection of architectural distortion (AD). Management of patients with multiple areas of AD is not established. OBJECTIVE. The purpose of this article is to compare pathologic outcomes between single and multiple areas of AD identified on DBT. METHODS. This retrospective study included 402 patients (mean age, 56 years) who underwent image-guided core needle biopsy of AD visualized on DBT between April 7, 2017, and April 16, 2019. Patients were classified as having a single or multiple areas of AD according to the presence of distinct areas of AD described in the clinical radiology reports. The pathologic diagnosis for each AD was on the basis of the most aggressive pathology identified on either biopsy or surgical excision, if performed. Patients with single and multiple areas of AD were compared. RESULTS. The sample included 372 patients with a single AD (145 benign, 121 high risk, 105 malignant, one other) and 30 patients with multiple visualized ADs, including 66 biopsied ADs (10 benign, 35 high risk, 21 malignant). At pathologic assessment on a per-lesion basis, multiple compared with single ADs showed higher frequency of high-risk pathology (53.0% vs 32.5%, p = .002) but no difference in frequency of malignancy (31.8% vs 28.2%, p = .56). In multivariable analysis of a range of patient-related characteristics, the presence of single versus multiple areas of AD was not independently associated with malignancy (p = .51). In patients with multiple areas of AD, the most aggressive pathology (benign, high risk, or malignant) across all ADs was not associated with the number of ADs (p = .73). In 8 of 24 patients with at least two ipsilateral biopsied ADs, the ipsilateral areas varied in terms of most aggressive pathology; in 5 of 10 patients with contralateral biopsied ADs, the contralateral areas varied in most aggressive pathology. CONCLUSION. The presence of multiple areas of AD, compared with a single AD, was significantly more likely to yield high-risk pathology but was not significantly different in yield of malignancy. In patients with multiple ADs, multiple ipsilateral or contralateral ADs commonly varied in pathologic classification (benign, high risk, or malignant). CLINICAL IMPACT. These findings may help guide management of AD visualized by DBT, including multiple ADs. For patients with multiple areas of AD, biopsy of all areas may be warranted given variation in pathologic diagnoses.

Diagnosis of architectural distortion on digital breast tomosynthesis using radiomics and deep learning

Purpose

To implement two Artificial Intelligence (AI) methods, radiomics and deep learning, to build diagnostic models for patients presenting with architectural distortion on Digital Breast Tomosynthesis (DBT) images.

Materials and Methods

A total of 298 patients were identified from a retrospective review, and all of them had confirmed pathological diagnoses, 175 malignant and 123 benign. The BI-RADS scores of DBT were obtained from the radiology reports, classified into 2, 3, 4A, 4B, 4C, and 5. The architectural distortion areas on craniocaudal (CC) and mediolateral oblique (MLO) views were manually outlined as the region of interest (ROI) for the radiomics analysis. Features were extracted using PyRadiomics, and then the support vector machine (SVM) was applied to select important features and build the classification model. Deep learning was performed using the ResNet50 algorithm, with the binary output of malignancy and benignity. The Gradient-weighted Class Activation Mapping (Grad-CAM) method was utilized to localize the suspicious areas. The predicted malignancy probability was used to construct the ROC curves, compared by the DeLong test. The binary diagnosis was made using the threshold of ≥ 0.5 as malignant.

Results

The majority of malignant lesions had BI-RADS scores of 4B, 4C, and 5 (148/175 = 84.6%). In the benign group, a substantial number of patients also had high BI-RADS ≥ 4B (56/123 = 45.5%), and the majority had BI-RADS ≥ 4A (102/123 = 82.9%). The radiomics model built using the combined CC+MLO features yielded an area under curve (AUC) of 0.82, the sensitivity of 0.78, specificity of 0.68, and accuracy of 0.74. If only features from CC were used, the AUC was 0.77, and if only features from MLO were used, the AUC was 0.72. The deep-learning model yielded an AUC of 0.61, significantly lower than all radiomics models (p<0.01), which was presumably due to the use of the entire image as input. The Grad-CAM could localize the architectural distortion areas.

Conclusion

The radiomics model can achieve a satisfactory diagnostic accuracy, and the high specificity in the benign group can be used to avoid unnecessary biopsies. Deep learning can be used to localize the architectural distortion areas, which may provide an automatic method for ROI delineation to facilitate the development of a fully-automatic computer-aided diagnosis system using combined AI strategies.

Stereotactic breast biopsies: Radiological-pathological concordance in a South African referral unit

Background: Stereotactic breast biopsies have become the gold standard for tissue diagnosis in non-palpable, sonographically occult breast abnormalities seen on mammogram. Only limited data exist in South Africa on the correlation between imaging findings and stereotactic biopsy histology.Objectives: To describe the mammographic findings and histological diagnosis in patients who underwent stereotactic breast biopsy at a referral hospital. In addition, to evaluate the proportion of malignancy in each Breast Imaging Reporting and Data System (BI-RADS) category.Method: A retrospective review of stereotactic breast biopsies was performed. Imaging characteristics (including BI-RADS category) and histological diagnosis were recorded. Using histopathology, cases were classified as benign, high-risk or malignant.Results: A total of 131 biopsies, from 123 patients, were included in the study. Most biopsies were performed on asymptomatic patients (79.3%, 104/131). The majority were categorised as BI-RADS 4 and demonstrated calcifications. Histology revealed a malignant diagnosis in 40 (30.5%) patients, a high-risk lesion in 8 (6.1%) patients and a benign diagnosis in 83 (63.4%) patients. There was a stepwise increase in the proportion of malignancy from BI-RADS category 3 to 5. When compared with surgical histology, the stereotactic biopsies demonstrated an overall ductal carcinoma in situ (DCIS) underestimation rate of 10.3%.Conclusion: Despite resource restrictions, stereotactic breast biopsies performed in a South African context produce radiological-pathological concordance in keeping with BI-RADS guidelines, as well as with local and international studies.

Management of Architectural Distortion on Digital Breast Tomosynthesis With Nonmalignant Pathology at Biopsy

BACKGROUND. Digital breast tomosynthesis (DBT) has led to increased detection and biopsy of architectural distortion, which may yield malignancy, radial scar, or other benign pathologies. Management of nonmalignant architectural distortion on DBT remains controversial. OBJECTIVE. The purpose of this study was to determine upgrade rates of architectural distortion on DBT from nonmalignant pathology at biopsy to malignancy at surgery. METHODS. This retrospective study included cases of mammographically detected architectural distortion from July 1, 2016, to June 30, 2019, that were nonmalignant at image-guided needle biopsy and underwent surgical excision. Mammographic examinations included digital 2D mammography and DBT. Imaging data were extracted from radiology reports. Upgrade rates were summarized using descriptive statistics. Features of upgraded and nonupgraded cases were compared using Pearson chi-square test and Wilcoxon signed rank test. RESULTS. The study included 129 cases of architectural distortion with nonmalignant pathology at biopsy that underwent excision in 125 women (mean age, 54 years; range, 23-90 years). At biopsy, 92 (71.3%) were radial scars and 37 (28.7%) were other nonmalignant pathologies. Of 66 radial scars without atypia at biopsy, one (1.5%) was upgraded to ductal carcinoma in situ (DCIS) at surgery and none to invasive cancer. Of 24 benign pathologies without atypia at biopsy, one was considered discordant. Of the 23 remaining concordant cases, one (4.3%) was upgraded to DCIS at surgery and none to invasive cancer. The overall upgrade rate to cancer of architectural distortion with concordant nonmalignant pathology at biopsy was 10.2% (13/128). The upgrade rate to cancer of architectural distortion without atypia was 2.2% (2/89) and with atypia was 28.2% (11/39). Explored features (age, personal or family breast cancer history, presentation by screening vs diagnostic mammography, breast density, associated mammographic findings, presence and size of ultrasound correlate, biopsy modality) showed no signifi-cant associations with upgrade risk (p > .05). CONCLUSION. Architectural distortion on DBT with concordant nonmalignant pathology at biopsy has an overall upgrade rate to malignancy at surgery of 10.2%. Architectural distortion without atypia has a low upgrade rate of 2.2%. CLINICAL IMPACT. Imaging surveillance can be considered for architectural distortion on DBT yielding radial scar without atypia or other concordant benign pathologies without atypia at biopsy.

Outcomes of Canceled Tomosynthesis-Guided Biopsy of Architectural Distortion Due to Nonvisualization

OBJECTIVE

Architectural distortion without a sonographic correlate is an indication for digital breast tomosynthesis-guided vacuum-assisted biopsy (DBT-VAB). However, when the finding is not visualized on the day of biopsy, the procedure is canceled. This study reports the outcomes of canceled DBT-VAB of architectural distortion due to nonvisualization.

METHODS

In this IRB-approved retrospective study, chart review was performed to identify DBT-VABs of architectural distortion at our institution between June 1, 2017, and November 1, 2020, that were canceled because of nonvisualization at the time of biopsy. Cases without follow-up imaging were excluded. Statistical analysis, including the frequency of cases yielding malignancy by the end of the study period, was performed.

RESULTS

In total, 7.2% (39/544) of architectural distortions recommended for biopsy during the study period were canceled because of nonvisualization, 30 of which had follow-up imaging and were included in the study. Mean patient age was 56 years (standard deviation [SD], 9.6 years) and mean follow-up time was 26.7 months (SD, 11.2 months; range, 8.4-50.9 months). During the follow-up period, 16.7% (5/30) underwent repeat biopsy attempt, with one malignant result (1/30, 3.3%; SD, 18%; 95% confidence interval: 0.6%-16.7%). In total, 86.7% (26/30) of cases were declared benign during the follow-up period and 10% (3/30) remained stable with a BI-RADS 3 assessment category.

CONCLUSION

During available follow-up, there was a low likelihood that distortions not visualized at the time of DBT-VAB represented malignancy (3.3%, 1/30). While this low malignancy rate is reassuring, imaging follow-up is warranted.

Breast lesions associated with mammographic architectural distortion: a study of 588 core needle biopsies

Architectural distortion (AD) on mammography is a localized alteration in the uniform texture of the breast characterized by lines radiating from a central point. Radiologic/pathologic correlation is challenging because the types of lesions associated with AD are not well defined and, thus, what signifies a discordant finding requiring excision is less clear. This retrospective case series was performed to elucidate the pathologic lesions associated with AD. Over a 6-year period, 588 core needle biopsies (CNBs) were performed for AD. Thirty-eight percent of the lesions were AD alone (single feature AD) and 62% had additional imaging features (multi-feature AD). Overall, 31% showed invasive carcinoma or ductal carcinoma in situ (DCIS), 37% showed benign lesions likely to correlate with AD, and 32% showed nonspecific benign findings. The invasive carcinomas tended to be low-grade (60%), ER-positive (98%), HER2-negative (98%), and often had lobular features (52%). Ninety-two percent were AJCC pathologic stage group I. Ninety-four cases of benign findings that correlated with AD without atypia underwent excision, and only one was found to have DCIS adjacent to the sclerosing lesion (1%). The remaining cases had benign findings without a clear correlate for AD. Sixty-eight cases without atypia underwent excision, and six multi-feature AD were upgraded to invasive carcinoma (9%). In conclusion, about one-third of CNBs for lesions associated with AD reveal carcinomas that are predominantly invasive, low-grade, ER-positive, HER2-negative, and low stage. Single-feature AD differed from multi-feature AD due to a lower number of carcinomas on CNB (18% vs 39%). For CNBs showing benign lesions on biopsy with a correlate for AD, the finding of malignancy on excision is low (1%). Radiologic/pathologic correlation and decisions to recommend excision will continue to be a challenge after CNB reveals nonspecific findings as some patients with multi-feature AD were found to have undetected invasive carcinomas.

The positive predictive value of vacuum assisted biopsy (VAB) in predicting final histological diagnosis for breast lesions of uncertain malignancy (B3 lesions): A systematic review & meta-analysis

INTRODUCTION

High-risk or B3 breast lesions are considered lesions of uncertain malignant potential and comprise between 5 and 12% of initial biopsy results. We sought to perform a systematic review and meta-analysis of studies published within the last twenty years to determine the pooled Positive Predictive Value (PPV) of VAB in selected B3 lesions.

METHODS

The study report is based on the guidelines of PRISMA and Meta-Analysis of Observational Studies in Epidemiology.

OUTCOMES

The primary outcome of this study was to determine the PPV of VAB in determining final histological diagnosis in B3 breast lesions using pooled estimates. The secondary outcomes were to determine if needle gauge or the re-classification of Lobular Carcinoma in Situ(LCIS) introduced in 2012 influenced pooled estimates.

RESULTS

78 studies incorporating 6,377 B3 lesions were included in this review, 1214 of which were upgraded to DCIS or invasive malignancy following surgical excision(19%). The pooled PPV of VAB in Atypical Ductal Hyperplasia(ADH) and Lobular Neoplasia(LN) were 0.79(CI 0.76-0.83) and 0.84(CI 0.8-0.88). VAB of Flat Epithelial Atypia(FEA), radial scar and papillary lesions with/without atypia all had a pooled PPV >90% (underestimation rates 7%, 1%, 5% and 3% respectively). Needle gauge size and the change in LCIS classification did not appear to influence underestimation rates on subgroup analysis.

CONCLUSION

Results from this meta-analysis suggests it is reasonable to perform VAB as definitive treatment for certain B3 lesions, specifically LN, FEA, radial scar, and papillary lesions when specific criteria are fulfilled. Surgical excision should continue as the mainstay of treatment for ADH.

Developing Asymmetries without Sonographic Correlate at Digital Breast Tomosynthesis

Background Digital breast tomosynthesis (DBT) has improved the accuracy of mammography, including resolving many breast asymmetries as overlapping breast tissue. The pathologic outcomes of persistent developing asymmetries visualized at DBT are not well established. Purpose To characterize the outcomes and the predictors of malignancy for developing asymmetries visualized at DBT without a sonographic correlate. Materials and Methods This retrospective study included all tomosynthesis-guided biopsies of developing asymmetries performed at a single institution from May 2017 through January 2020. A reader study including three breast imaging radiologists determined interrater agreement and inclusion into the study. Electronic medical records were used to extract patient characteristics, imaging characteristics, and pathologic diagnoses. The Wilcoxon rank sum test, Fisher exact test, and χ² test were used to analyze correlations of patient and imaging characteristics with likelihood of malignancy. Results The reader study included 95 DBT examinations with moderate interrater reliability (Fleiss κ = 0.45). There was majority reader agreement in 85 of the 95 DBT examinations (89%) of 83 women (median age, 56 years; interquartile range, 47-69 years), and this finalized the study data set. At pathologic examination, most asymmetries (68 of 85, 80%) were benign, with common diagnoses being fibrocystic change (n = 20), stromal fibrosis (n = 10), and fat necrosis (n = 10). The overall malignancy rate was 20% (17 of 85 asymmetries; 95% CI: 12, 29); 15 of the 17 malignancies (88%) were invasive cancers. Malignancies were more common in women with a personal history of breast cancer (35% vs 10%, P = .02). Conclusion In 85 developing asymmetries visualized at digital breast tomosynthesis without a sonographic correlate, there was a 20% (95% CI: 12, 29) malignancy rate, which was higher than the rates of malignancy for a developing asymmetry detected at digital mammography. © RSNA, 2021 See also the editorial by Skaane in this issue.

Pathological outcome of sonographically occult architectural distortions (AD) visible only on digital breast tomosynthesis, and comparison with AD visible also on 2D mammography

PURPOSE

To evaluate the rates of malignant and of high-risk lesions among sonographically occult architectural distortions (AD) visible only on digital breast tomosynthesis (DBT) and compare them with AD visible on 2D mammography (2D) and DBT.

METHOD

The records of 1104 DBT-vacuum assisted biopsies (DBT-VAB) were retrospectively reviewed and 218 cases of AD were identified. Complete radiologic examinations and pathologic results were available for 113 sonographically occult AD (1 clinically-detected, 112 clinically-occult). 2D and DBT images were reviewed and AD were divided into a "DBT-detected" group (visible on only DBT) and a "2D-detected" group (visible both in 2D and DBT). The rates of malignant and of high-risk lesions in the "DBT-detected" AD group were calculated and compared to those of the "2D-detected" AD group.

RESULTS

Thirty-five (31%) of 113 AD were assessed as "DBT-detected", while 78 (69%) as "2D-detected". DBT-VAB results were benign lesions in 63 (56%) AD, high-risk lesions in 32 (28%) AD and malignant lesions in 18 (16%) AD. Four (12.5%) high-risk lesions were upgraded to malignancy at surgery. Based on final pathology, the malignancy rate was significantly higher in the "DBT-detected" group than the "2D-detected" group (34% [12/35 cases] vs 13% [10/78]; p < 0.05). The high-risk lesion rates were 32% (11/35 cases) in the "DBT-detected" group and 22% (17/78 cases) in the "2D-detected" group (p > 0.05).

CONCLUSIONS

AD visible on only DBT proved to be malignant in about one third of cases, which exceeded the malignancy rate of AD visible on also 2D. A similar proportion of DBT-only AD was represented by high-risk lesions.