Value of breast MRI for patients with a biopsy showing atypical ductal hyperplasia (ADH)

Meta-analysis: Radial Scar and Breast MRI

BACKGROUND

The implementation of digital breast tomosynthesis has increased the detection of radial scar (RS). Managing this finding may be experienced as a clinical dilemma in daily practice. Breast Contrast-Enhanced MRI (CE-BMR) is a known modality in case of problem-solving tool for mammographic abnormalities. However, the data about AD and CE-BMR are scant.

OBJECTIVE

The purpose was to estimate the benefit of CE-BMR in the setting of RS detected mammographically through a systematic review and meta-analysis of the literature.

METHODS

A search of MEDLINE and EMBASE databases were conducted in 2022. Based on the PRISMA guidelines, an analysis was performed. The primary endpoint was the correlation between CE-BMR findings and definite outcome for RS (pure RS versus RS associated with atypia or malignancy).

RESULTS

Three studies were available. The negative predictive value (NPV) was 100% for each.

CONCLUSION

The high NPV could allow for deferral of a biopsy in favor of a short-interval imaging follow-up in the setting of a negative CE-BMR.

Contrast-enhanced ultrasound to predict malignant upgrading of atypical ductal hyperplasia

BACKGROUND

A malignancy might be found at surgery in cases of atypical ductal hyperplasia (ADH) diagnosed via US-guided core needle biopsy (CNB). The objective of this study was to investigate the diagnostic performance of contrast-enhanced ultrasound (CEUS) in predicting ADH diagnosed by US-guided CNB that was upgraded to malignancy after surgery.

METHODS

In this retrospective study, 110 CNB-diagnosed ADH lesions in 109 consecutive women who underwent US, CEUS, and surgery between June 2018 and June 2023 were included. CEUS was incorporated into US BI-RADS and yielded a CEUS-adjusted BI-RADS. The diagnostic performance of US BI-RADS and CEUS-adjusted BI-RADS for ADH were analyzed and compared.

RESULTS

The mean age of the 109 women was 49.7 years ± 11.6 (SD). The upgrade rate of ADH at CNB was 48.2% (53 of 110). The sensitivity, specificity, positive predictive value, and negative predictive value of CEUS for identification of malignant upgrading were 96.2%, 66.7%,72.9%, and 95.0%, respectively, based on BI-RADS category 4B threshold. The two false-negative cases were low-grade ductal carcinoma in situ. Compared with the US, CEUS-adjusted BI-RADS had better specificity for lesions smaller than 2 cm (76.7% vs. 96.7%, P = 0.031). After CEUS, 16 (10 malignant and 6 nonmalignant) of the 45 original US BI-RADS category 4A lesions were up-classified to BI-RADS 4B, and 3 (1 malignant and 2 nonmalignant) of the 41 original US BI-RADS category 4B lesions were down-classified to BI-RADS 4A.

CONCLUSIONS

CEUS is helpful in predicting malignant upgrading of ADH, especially for lesions smaller than 2 cm and those classified as BI-RADS 4A and 4B on ultrasound.

Problem-solving Breast MRI

Breast MRI has high sensitivity and negative predictive value, making it well suited to problem solving when other imaging modalities or physical examinations yield results that are inconclusive for the presence of breast cancer. Indications for problem-solving MRI include equivocal or uncertain imaging findings at mammography and/or US; suspicious nipple discharge or skin changes suspected to represent an abnormality when conventional imaging results are negative for cancer; lesions categorized as Breast Imaging Reporting and Data System 4, which are not amenable to biopsy; and discordant radiologic-pathologic findings after biopsy. MRI should not precede or replace careful diagnostic workup with mammography and US and should not be used when a biopsy can be safely performed. The role of MRI in characterizing calcifications is controversial, and management of calcifications should depend on their mammographic appearance because ductal carcinoma in situ may not appear enhancing on MR images. In addition, ductal carcinoma in situ detected solely with MRI is not associated with a higher likelihood of an upgrade to invasive cancer compared with ductal carcinoma in situ detected with other modalities. MRI for triage of high-risk lesions is a subject of ongoing investigation, with a possible future role for MRI in decreasing excisional biopsies. The accuracy of MRI is likely to increase with the use of advanced techniques such as deep learning, which will likely expand the indications for problem-solving MRI. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Imaging Characteristics of and Multidisciplinary Management Considerations for Atypical Ductal Hyperplasia and Flat Epithelial Atypia: Review of Current Literature

High-risk lesions of the breast are frequently encountered in percutaneous biopsy specimens. While benign, these lesions have historically undergone surgical excision due to their potential to be upgraded to malignancy. However, there is emerging evidence that a tailored management approach should be considered to reduce overtreatment of these lesions. Flat epithelial atypia (FEA) and atypical ductal hyperplasia (ADH) are two of the most commonly encountered high-risk lesions. FEA has been shown to have a relatively low rate of progression to malignancy, and some guidelines are now recommending observation over routine excision in select cases. Selective observation may be reasonable in cases where the target lesion is small and completely removed at biopsy and when there are no underlying risk factors, such as a history of breast cancer or genetic mutation or concurrent ADH. ADH has the highest potential upgrade rate to malignancy of all the high-risk lesions. Most society guidelines continue to recommend surgical excision of this lesion. More recently, some literature suggests that ADH lesions that appear completely removed at biopsy, involve limited foci (less than two or three) with no necrosis or significant atypia, manifest as a small group of mammographic calcifications, or demonstrate no enhancement at MRI may be reasonable for observation. Ultimately, management of all high-risk lesions must be based on a multidisciplinary approach that considers all patient, radiologic, clinical, and histopathologic factors. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Active Surveillance for Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ

Atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) are relatively common breast lesions on the same spectrum of disease. Atypical ductal hyperblasia is a nonmalignant, high-risk lesion, and DCIS is a noninvasive malignancy. While a benefit of screening mammography is early cancer detection, it also leads to increased biopsy diagnosis of noninvasive lesions. Previously, treatment guidelines for both entities included surgical excision because of the risk of upgrade to invasive cancer after surgery and risk of progression to invasive cancer for DCIS. However, this universal management approach is not optimal for all patients because most lesions are not upgraded after surgery. Furthermore, some DCIS lesions do not progress to clinically significant invasive cancer. Overtreatment of high-risk lesions and DCIS is considered a burden on patients and clinicians and is a strain on the health care system. Extensive research has identified many potential histologic, clinical, and imaging factors that may predict ADH and DCIS upgrade and thereby help clinicians select which patients should undergo surgery and which may be appropriate for active surveillance (AS) with imaging. Additionally, multiple clinical trials are currently underway to evaluate whether AS for DCIS is feasible for a select group of patients. Recent advances in MRI, artificial intelligence, and molecular markers may also have an important role to play in stratifying patients and delineating best management guidelines. This review article discusses the available evidence regarding the feasibility and limitations of AS for ADH and DCIS, as well as recent advances in patient risk stratification.

Breast MRI assists in decision-making for surgical excision of atypical ductal hyperplasia

BACKGROUND

Atypical ductal hyperplasia diagnosed on percutaneous breast biopsy typically undergoes surgical excision, upgrading to invasive breast cancer or ductal carcinoma in situ in 10% to 53%. In efforts to limit excision to those with highest upgrade risk, we sought to determine if breast magnetic resonance imaging has value in predicting upgrade. In this study, we will describe magnetic resonance imaging presentation of atypical ductal hyperplasia and assess magnetic resonance imaging accuracy in predicting upgrade.

METHODS

All female patients ≥18 years with atypical ductal hyperplasia on percutaneous breast biopsy undergoing magnetic resonance imaging from 2008 to 2020 were included. Patient demographics, imaging presentation, magnetic resonance imaging enhancement kinetic curves, and pathology features were captured. Categorical variables were analyzed using Fisher exact to test for association between variables and upgrade. Continuous variables were analyzed using t tests.

RESULTS

Magnetic resonance imaging was performed for 125 percutaneous breast biopsy with atypical ductal hyperplasia: 67 after and 58 before atypical ductal hyperplasia diagnosis. On magnetic resonance imaging, atypical ductal hyperplasia site had no enhancement in 45 (36%), nonmass enhancement in 50 (40%), and mass enhancement in 30 (24%). In total, 28% had atypical ductal hyperplasia diagnosed by magnetic resonance imaging-guided percutaneous breast biopsy. Surgical excision was performed for 96 (76.8%) and 15 (15.6%) upgraded (11 ductal carcinoma in situ, 4 invasive breast cancer). All 15 upgrades had enhancement. Any kinetic pattern enhancement was significantly associated with upgrade (P = .009) with upgrade most strongly associated with type III washout. The lowest risk for upgrade was pure atypical ductal hyperplasia and no magnetic resonance imaging enhancement (0%, n = 25).

CONCLUSIONS

Active monitoring may be safely offered to women with pure atypical ductal hyperplasia on percutaneous breast biopsy when magnetic resonance imaging shows no enhancement. Any enhancement at atypical ductal hyperplasia site, particularly type III washout kinetics, should continue to undergo excision.

Inter-observer agreement in the diagnosis of breast atypical ductal hyperplasia: A systematic review

OBJECTIVE

To review the concordance between pathologists in the diagnosis of atypical ductal hyperplasia of the breast.

METHODS

Systematic review of articles registered in the PubMed database with the terms "pathologists" and "atypical ductal hyperplasia", "atypical ductal hyperplasia" and "interobserver variability", in Embase with "interobserver agreement in atypical ductal hyperplasia" and Lilacs with the terms in Spanish "patólogos" and "hiperplasia ductal atípica", without the use of filters, between 03/16/2022 and 03/26/2022 searching for articles that assess inter-observer agreement in the diagnosis of atypical ductal hyperplasia by using the kappa statistic. Review articles, conference proceedings, and commentaries were excluded.

RESULTS

With the search terms, 507 publications were found. Of these, 491 were excluded from the screening by title and abstract. Of the full reading of the remaining articles, 6 were selected for qualitative analysis. The kappa values ranged from slight agreement, kappa = 0.17, to substantial agreement, 0.69 obtained from pathologists dedicated or experienced in breast pathology and who received a prior tutorial session to review the general criteria for atypia.

CONCLUSIONS

This study reviews the reproducibility in the diagnosis of atypical ductal hyperplasia. A better concordance was obtained with a previous teaching process offered to pathologists dedicated or experienced in breast pathology.

Meta-analysis: Architectural distortion and breast MRI

BACKGROUND

The implementation of digital breast tomosynthesis has increased the detection of architectural distortion (AD). Managing this finding may be experienced as a clinical dilemma in daily practice. Breast Contrast-Enhanced MRI (CE-BMR) is a known modality in case of problem-solving tool for mammographic abnormalities. However, the data about AR and CE-BMR are scant.

OBJECTIVE

The purpose was to estimate the benefit of CE-BMR in the setting of architectural distortion detected mammographically through a systematic review and meta-analysis of the literature.

METHODS

A search of MEDLINE and EMBASE databases were conducted in 2020. Based on the PRISMA guidelines, an analysis was performed using the chi-square test of independence to determine if there was a significant association between the result of the test (positive or negative) and the participant condition (malignant or non-malignant).

RESULTS

Four studies were available. The negative predictive value (NPV) was 98.3% to 100%. The result of the chi-square indicated that there was significant association between the participant test result and the participant condition for the included publications (X(1,175)2= 84.051, p = 0.0001).

CONCLUSIONS

The high NPV could allow for deferral of a biopsy in favor of a short-interval imaging follow-up in the setting of a negative CE-BMR.

Role of breast MRI in predicting histologic upgrade risks in high-risk breast lesions: A review

PURPOSE

This article reviews the frequency, upgrade rate and valuable imaging characteristics for predicting the histologic upgrade risks of high-risk lesions on MRI, so as to provide a reference for the management of the lesions.

METHODS

A comprehensive search for relevant publications from January 2011 to January 2021 was conducted in the PubMed database. The frequency, upgrade rate and valuable imaging characteristics for predicting the upgrade risks of high-risk lesions on MRI included in the articles were reviewed, and the management of high-risk lesions was provided with a reference according to the review results.

RESULTS AND CONCLUSIONS

In terms of management options, Atypical ductal hyperplasia (ADH) and Lobular neoplasia (LN) (the top two high-risk lesions with the highest upgrade rate and frequency) were treated with surgical resection. However, the final treatment decision for other high-risk lesions should be made by a multidisciplinary committee. In terms of the value of breast MRI in predicting the upgrade risks of high-risk lesions, the lesions that were confirmed to upgrade after surgery showed some enhancement characteristics, especially for ADH and LN. At the same time, Dynamic contrast-enhanced MRI (DCE-MRI) has a high negative predictive value (NPV) in predicting the upgrade risks of the high-risk lesions, hence misdiagnosis and overtreatment can be reduced. Diffusion-weighted imaging (DWI) and relative apparent diffusion coefficient (rADC) can be used to predict the upgrade risks of the lesions, and the ADC of upgraded lesions is lower than that of non-upgraded lesions. However, these conclusions should be confirmed by further studies.

Diagnostic value of radiomics and machine learning with dynamic contrast-enhanced magnetic resonance imaging for patients with atypical ductal hyperplasia in predicting malignant upgrade

Purpose

To investigate whether radiomics features extracted from magnetic resonance imaging (MRI) of patients with biopsy-proven atypical ductal hyperplasia (ADH) coupled with machine learning can differentiate high-risk lesions that will upgrade to malignancy at surgery from those that will not, and to determine if qualitatively and semi-quantitatively assessed imaging features, clinical factors, and image-guided biopsy technical factors are associated with upgrade rate.

Methods

This retrospective study included 127 patients with 139 breast lesions yielding ADH at biopsy who were assessed with multiparametric MRI prior to biopsy. Two radiologists assessed all lesions independently and with a third reader in consensus according to the BI-RADS lexicon. Univariate analysis and multivariate modeling were performed to identify significant radiomic features to be included in a machine learning model to discriminate between lesions that upgraded to malignancy on surgery from those that did not.

Results

Of 139 lesions, 28 were upgraded to malignancy at surgery, while 111 were not upgraded. Diagnostic accuracy was 53.6%, specificity 79.2%, and sensitivity 15.3% for the model developed from pre-contrast features, and 60.7%, 86%, and 22.8% for the model developed from delta radiomics datasets. No significant associations were found between any radiologist-assessed lesion parameters and upgrade status. There was a significant correlation between the number of specimens sampled during biopsy and upgrade status (p = 0.003).

Conclusion

Radiomics analysis coupled with machine learning did not predict upgrade status of ADH. The only significant result from this analysis is between the number of specimens sampled during biopsy procedure and upgrade status at surgery.

Management of High-Risk Breast Lesions

High-risk breast lesions (HRLs) are a group of heterogeneous lesions that can be associated with a synchronous or adjacent breast cancer and that confer an elevated lifetime risk of breast cancer. Management of HRLs after core needle biopsy may include close imaging and clinical follow-up or excisional biopsy to evaluate for cancer. This article reviews histologic features and clinical presentation of each of the HRLs, current evidence with regard to management, and guidelines from the American Society of Breast Surgeons and National Comprehensive Cancer Network. In addition, imaging surveillance and risk-reduction strategies for women with HRLs are discussed.

Prospective Multicenter Study Validate a Prediction Model for Surgery Uptake Among Women with Atypical Breast Lesions

BACKGROUND

Diagnosis of atypical breast lesions (ABLs) leads to unnecessary surgery in 75-90% of women. We have previously developed a model including age, complete radiological target excision after biopsy, and focus size that predicts the probability of cancer at surgery. The present study aimed to validate this model in a prospective multicenter setting.

- METHODS

Women with a recently diagnosed ABL on image-guided biopsy were recruited in 18 centers, before wire-guided localized excisional lumpectomy. Primary outcome was the negative predictive value (NPV) of the model.

RESULTS

The NOMAT model could be used in 287 of the 300 patients included (195 with ADH). At surgery, 12 invasive (all grade 1), and 43 in situ carcinomas were identified (all ABL: 55/287, 19%; ADH only: 49/195, 25%). The area under the receiving operating characteristics curve of the model was 0.64 (95% CI 0.58-0.69) for all ABL, and 0.63 for ADH only (95% CI 0.56-0.70). For the pre-specified threshold of 20% predicted probability of cancer, NPV was 82% (77-87%) for all ABL, and 77% (95% CI 71-83%) for patients with ADH. At a 10% threshold, NPV was 89% (84-94%) for all ABL, and 85% (95% CI 78--92%) for the ADH. At this threshold, 58% of the whole ABL population (and 54% of ADH patients) could have avoided surgery with only 2 missed invasive cancers.

CONCLUSION

The NOMAT model could be useful to avoid unnecessary surgery among women with ABL, including for patients with ADH.

CLINICAL TRIAL REGISTRATION

NCT02523612.

Risk for Upgrade to Malignancy After Breast Core Needle Biopsy Diagnosis of Lobular Neoplasia: A Systematic Review and Meta-Analysis

PURPOSE

Lobular neoplasia (LN) detected on breast core needle biopsy is frequently managed with surgical excision because of concern for undersampled malignancy. The authors performed a systematic review and meta-analysis to estimate the risk for upgrade to malignancy in the setting of imaging-concordant classic LN diagnosed on core biopsy.

METHODS

PubMed and Embase were searched for original articles published from 1998 to 2020 that reported rates of upgrade to malignancy for classic LN, including atypical lobular hyperplasia (ALH) and classic lobular carcinoma in situ (LCIS). Two reviewers extracted study data and assessed the following quality criteria: exclusion of variant LCIS, exclusion of imaging-discordant lesions, and outcome reporting for ≥70% of lesions. For studies meeting all criteria, pooled risks for upgrade to any malignancy (invasive carcinoma or ductal carcinoma in situ) and invasive malignancy for all LN, ALH, and LCIS were estimated using random-effects models.

RESULTS

For 65 full-text articles included in the review, the risk for upgrade to any malignancy ranged from 0% to 45%. Among the 16 studies that met all quality criteria for the meta-analysis, pooled risks for upgrade to any malignancy were 3.1% (95% confidence interval [CI], 1.8%-5.2%) for all LN, 2.5% (95% CI, 1.6%-3.9%) for ALH, and 5.8% (95% CI, 2.9%-11.3%) for LCIS. Risks for upgrade to invasive malignancy were 1.3% (95% CI, 0.7%-2.4%) for all LN, 0.4% (95% CI, 0.0%-4.2%) for ALH, and 3.5% (95% CI, 2.0%-5.9%) for LCIS.

CONCLUSIONS

The risk for upgrade to malignancy for LN found on breast biopsy is low. Imaging surveillance can likely be offered as an alternative to surgical management for LN, particularly for ALH.

Positive predictive value for malignancy of uncertain malignant potential (B3) breast lesions diagnosed on vacuum-assisted biopsy (VAB): is surgical excision still recommended?

PURPOSE

Breast lesions classified as of "uncertain malignant potential" represent a heterogeneous group of abnormalities with an increased risk of associated malignancy. Clinical management of B3 lesions diagnosed on vacuum-assisted breast biopsy (VABB) is still challenging: surgical excision is no longer the only available treatment and VABB may be sufficient for therapeutic excision. The aim of the present study is to evaluate the positive predictive value (PPV) for malignancy in B3 lesions that underwent surgical excision, identifying possible upgrading predictive factors and characterizing the malignant lesions eventually diagnosed. These results are compared with a subset of patients with B3 lesions who underwent follow-up.

METHODS

A total of 1250 VABBs were performed between January 2006 and December 2017 at our center. In total, 150 B3 cases were diagnosed and 68 of them underwent surgical excision. VABB findings were correlated with excision histology. A PPV for malignancy for each B3 subtype was derived.

RESULTS

The overall PPV rate was 28%, with the highest upgrade rate for atypical ductal hyperplasia (41%), followed by classical lobular neoplasia (29%) and flat epithelial atypia (11%). Only two cases of carcinoma were detected in the follow-up cohort, both associated with atypical ductal hyperplasia at VABB.

CONCLUSION

Open surgery is recommended in case of atypical ductal hyperplasia while, for other B3 lesions, excision with VABB only may be an acceptable alternative if radio-pathological correlation is assessed, if all microcalcifications have been removed by VABB, and if the lesion lacks high-risk cytological features.

KEY POINTS

• Surgical treatment is strongly recommended in case of ADH, while the upgrade rate in case of pure FEA, especially following complete microcalcification removal by VABB, may be sufficiently low to advice surveillance as a management strategy. • The use of 11-G- or 8-G-needle VABB, resulting in possible complete diagnostic excision of the lesion, can be an acceptable alternative in case of RS, considering open surgery only for selected high-risk patients. • LN management is more controversial: surgical excision may be recommended following classical LN diagnosis on breast biopsy if an additional B3 lesion is concurrently detected while in the presence of isolated LN with adequate radiological-pathological correlation follow-up alone could be an acceptable option.

Prospective Analysis Using a Novel CNN Algorithm to Distinguish Atypical Ductal Hyperplasia From Ductal Carcinoma in Situ in Breast

INTRODUCTION

We previously developed a convolutional neural networks (CNN)-based algorithm to distinguish atypical ductal hyperplasia (ADH) from ductal carcinoma in situ (DCIS) using a mammographic dataset. The purpose of this study is to further validate our CNN algorithm by prospectively analyzing an unseen new dataset to evaluate the diagnostic performance of our algorithm.

MATERIALS AND METHODS

In this institutional review board-approved study, a new dataset composed of 280 unique mammographic images from 140 patients was used to test our CNN algorithm. All patients underwent stereotactic-guided biopsy of calcifications and underwent surgical excision with available final pathology. The ADH group consisted of 122 images from 61 patients with the highest pathology diagnosis of ADH. The DCIS group consisted of 158 images from 79 patients with the highest pathology diagnosis of DCIS. Two standard mammographic magnification views (craniocaudal and mediolateral/lateromedial) of the calcifications were used for analysis. Calcifications were segmented using an open source software platform 3D slicer and resized to fit a 128 × 128 pixel bounding box. Our previously developed CNN algorithm was used. Briefly, a 15 hidden layer topology was used. The network architecture contained 5 residual layers and dropout of 0.25 after each convolution. Diagnostic performance metrics were analyzed including sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve. The "positive class" was defined as the pure ADH group in this study and thus specificity represents minimizing the amount of falsely labeled pure ADH cases.

RESULTS

Area under the receiver operating characteristic curve was 0.90 (95% confidence interval, ± 0.04). Diagnostic accuracy, sensitivity, and specificity was 80.7%, 63.9%, and 93.7%, respectively.

CONCLUSION

Prospectively tested on new unseen data, our CNN algorithm distinguished pure ADH from DCIS using mammographic images with high specificity.

Atypical ductal hyperplasia: breast DCE-MRI can be used to reduce unnecessary open surgical excision

PURPOSE

To evaluate the diagnostic performance of dynamic contrast-enhanced (DCE)-MRI in predicting malignancy after percutaneous biopsy diagnosis of atypical ductal hyperplasia (ADH).

METHODS AND MATERIALS

In this retrospective study, 68 lesions (66 women) with percutaneous biopsy diagnosis of ADH and pre-operative breast DCE-MRI performed between January 2016 and December 2017 were included. Two radiologists reviewed in consensus mammography, ultrasound, and MR images. The final diagnosis after surgical excision was used as standard of reference. Clinical and imaging features were compared in patients with and without upgrade to malignancy after surgery. The diagnostic performance of DCE-MRI in predicting malignant upgrade was evaluated.

RESULTS

A 9-gauge vacuum-assisted biopsy was performed in 40 (58.8%) cases and a 14-gauge core needle biopsy in 28 (41.2%) cases. Upgrade to malignancy was observed in 17/68 (25%) lesions, including 4/17 (23.5%) cases of invasive cancer and 13/17 (76.5%) cases of ductal carcinoma in situ (DCIS). In 16/17 (94.1%) malignant and 20/51 (39.2%) benign lesions, a suspicious enhancement could be recognized in DCE-MRI. The malignant lesion without suspicious enhancement was a low-grade DCIS (4 mm size). Sensitivity, specificity, positive predictive value, and negative predictive value of DCE-MRI on predicting malignancy were respectively 94.1%, 60.7%, 44.4%, and 96.8%. No other clinical or imaging features were significantly different in patients with and without upgrade to malignancy.

CONCLUSION

After a percutaneous biopsy diagnosis of ADH, malignancy can be ruled out in most of the cases, if no suspicious enhancement is present in the biopsy area at DCE-MRI. Breast DCE-MRI may be used to avoid surgery in more than half of the patients with final benign diagnosis.

KEY POINTS

• Breast DCE-MRI can safely rule out malignancy if no suspicious enhancement is present in the biopsy area after a percutaneous biopsy diagnosis of ADH. • All cases of upgrade to high-grade DCIS and invasive cancers can be identified at breast DCE-MRI after a percutaneous biopsy diagnosis of ADH. • Breast DCE-MRI may be used to avoid surgery in more than half of the patients with final benign diagnosis.

Can breast MRI accurately exclude malignancy in mammographic architectural distortion?

OBJECTIVES

To investigate the diagnostic accuracy of problem-solving breast magnetic resonance imaging (MRI) in excluding malignancy in a cohort of patients diagnosed with mammographic architectural distortion (MAD).

METHODS

The Institutional Review Board approved the study. Imaging database with 40,245 breast MRIs done between January 2008 and September 2018 was retrospectively reviewed. The study included all exams considered problem-solving MRI for MAD. Two radiologists reviewed the imaging data. Outcome was determined by the pathology results of biopsy/surgical excision or at least 1 year of clinical and radiological follow-up. Predictors for malignancy were examined, and appropriate statistical tests were applied.

RESULTS

One hundred seventy-five patients (median age 53 years) fulfilled the inclusion criteria and formed the study cohort. No cancers were diagnosed in 106 patients with a negative MRI. Out of 69 women with positive MRI findings, 48 (70%) had benign outcome defined either by pathology result or by negative follow-up, and 21 (30%) yielded malignancy. Malignancy was significantly associated with positive MRI (p < 0.001) and older age (p = 0.014). Falsely positive MRIs were frequently found in women with radial scars. The sensitivity, specificity, negative predictive value, positive predictive value, and overall accuracy of breast MRI were 100% (95% CI 84 to 100%), 68% (CI 61 to 76%), 100% (CI 95 to 100%), 30% (CI 26 to 36%), and 73% (95% CI 66-79), respectively.

CONCLUSION

A negative breast MRI in patients with MAD was reliable in excluding malignancy in this cohort and may have a role as a precision medicine tool for avoiding unnecessary interventions.

KEY POINTS

• MRI shows a high negative predictive value in MAD cases. • MRI displays low accuracy in differentiating malignancy from RS. • MRI is a reliable non-invasive method to exclude malignancy in women with mammographic architectural distortion, potentially avoiding unnecessary biopsies and surgeries.

Atypical Ductal Hyperplasia and Lobular Neoplasia: Update and Easing of Guidelines

OBJECTIVE. Atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and lobular carcinoma in situ (LCIS) are among high-risk lesions that have been previously recommended for surgical excision when diagnosed on core needle biopsy. Recent studies have examined whether imaging surveillance is a reasonable alternative to surgical management for these lesions. This article synthesizes the evidence regarding management of atypical hyperplasia and LCIS diagnosed on core needle biopsy and clinical implications of these diagnoses on future breast cancer risk as well as highlights areas of further research needed to improve practice guidelines for these high-risk lesions. CONCLUSION. Although surgical excision is still recommended after diagnosis of ADH on core needle biopsy, in specific circumstances ALH and LCIS can safely be managed by imaging surveillance.

Upgrade Rate of Percutaneously Diagnosed Pure Atypical Ductal Hyperplasia: Systematic Review and Meta-Analysis of 6458 Lesions

Background Management of percutaneously diagnosed pure atypical ductal hyperplasia (ADH) is an unresolved clinical issue. Purpose To calculate the pooled upgrade rate of percutaneously diagnosed pure ADH. Materials and Methods A search of MEDLINE and EMBASE databases was performed in October 2018. Preferred Reporting Items for Systematic Reviews and Meta-Analyses, or PRISMA, guidelines were followed. A fixed- or random-effects model was used, along with subgroup and meta-regression analyses. The Newcastle-Ottawa scale was used for study quality, and the Egger test was used for publication bias. Results Of 521 articles, 93 were analyzed, providing data for 6458 ADHs (5911 were managed with surgical excision and 547 with follow-up). Twenty-four studies used core-needle biopsy; 44, vacuum-assisted biopsy; 21, both core-needle and vacuum-assisted biopsy; and four, unspecified techniques. Biopsy was performed with stereotactic guidance in 29 studies; with US guidance in nine, with MRI guidance in nine, and with mixed guidance in eight. Overall heterogeneity was high (I² = 80%). Subgroup analysis according to management yielded a pooled upgrade rate of 29% (95% confidence interval [CI]: 26%, 32%) for surgically excised lesions and 5% (95% CI: 4%, 8%) for lesions managed with follow-up (P < .001). Heterogeneity was entirely associated with surgically excised lesions (I² = 78%) rather than those managed with follow-up (I² = 0%). Most variability was explained by guidance and needle caliper (P = .15). At subgroup analysis of surgically excised lesions, the pooled upgrade rate was 42% (95% CI: 31%, 53%) for US guidance, 23% (95% CI: 19%, 27%) for stereotactic biopsy, and 32% (95% CI: 22%, 43%) for MRI guidance, with heterogeneity (52%, 63%, and 56%, respectively) still showing the effect of needle caliper. When the authors considered patients with apparent complete lesion removal after biopsy (subgroups in 14 studies), the pooled upgrade rate was 14% (95% CI: 8%, 23%). Study quality was low to medium; the risk of publication bias was low (P = .10). Conclusion Because of a pooled upgrade rate higher than 2% (independent of biopsy technique, needle size, imaging guidance, and apparent complete lesion removal), atypical ductal hyperplasia diagnosed with percutaneous needle biopsy should be managed with surgical excision. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Brem in this issue.

Accuracy of Distinguishing Atypical Ductal Hyperplasia From Ductal Carcinoma In Situ With Convolutional Neural Network-Based Machine Learning Approach Using Mammographic Image Data

OBJECTIVE. The purpose of this study was to test the hypothesis that convolutional neural networks can be used to predict which patients with pure atypical ductal hyperplasia (ADH) may be safely monitored rather than undergo surgery. MATERIALS AND METHODS. A total of 298 unique images from 149 patients were used for our convolutional neural network algorithm. A total of 134 images from 67 patients with ADH that had been diagnosed by stereotactic-guided biopsy of calcifications but had not been upgraded to ductal carcinoma in situ or invasive cancer at the time of surgical excision. A total of 164 images from 82 patients with mammographic calcifications indicated that ductal carcinoma in situ was the final diagnosis. Two standard mammographic magnification views of the calcifications (a craniocaudal view and a mediolateral or lateromedial view) were used for analysis. Calcifications were segmented using an open-source software platform and images were resized to fit a bounding box of 128 × 128 pixels. A topology with 15 hidden layers was used to implement the convolutional neural network. The network architecture contained five residual layers and dropout of 0.25 after each convolution. Patients were randomly separated into a training-and-validation set (80% of patients) and a test set (20% of patients). Code was implemented using open-source software on a workstation with an open-source operating system and a graphics card. RESULTS. The AUC value was 0.86 (95% CI, ± 0.03) for the test set. Aggregate sensitivity and specificity were 84.6% (95% CI, ± 4.0%) and 88.2% (95% CI, ± 3.0%), respectively. Diagnostic accuracy was 86.7% (95% CI, ± 2.9). CONCLUSION. It is feasible to apply convolutional neural networks to distinguish pure atypical ductal hyperplasia from ductal carcinoma in situ with the use of mammographic images. A larger dataset will likely result in further improvement of our prediction model.

Use of Breast Magnetic Resonance Imaging in Women Diagnosed With Atypical Ductal Hyperplasia at Core Needle Biopsy Helps Select Women for Surgical Excision

PURPOSE

The study sought to investigate the role of breast magnetic resonance imaging (MRI) in patients diagnosed with atypical ductal hyperplasia (ADH) at core needle biopsy (CNB).

METHODS

The breast MRI database at our centre was queried for studies performed between January 2010 and December 2016 for the clinical indication of ADH diagnosed at CNB. Medical files were reviewed for demographic data, clinical information, and radiology and pathology reports. Pathological results of the surgical specimens were considered the gold standard for comparison with breast MRI findings. In women not undergoing excision, at least 2 years of follow-up was used to ascertain the benign nature of the finding.

RESULTS

Fifty patients were included in the study. Thirty-one (62%) patients had surgical excision of the ADH lesion, and 7 (23%) were upgraded to malignancy. Breast MRI accurately identified 6 of the 7 cases. Six of the 12 women (50%) with positive MRI findings at the biopsy site were upgraded to malignancy on surgical pathology, compared with only 1 of 19 (5%) with negative MRI findings. Forty-nine percent of the women with a negative MRI did not undergo surgical excision of the ADH lesion, compared with 8% of the women with a positive MRI (P = .009), with no cancer diagnosed during follow-up. The sensitivity, specificity, negative predictive value, and positive predictive value of breast MRI for predicting upgrade to malignancy were 86%, 83%, 97%, and 46%, respectively.

CONCLUSIONS

MRI may have a role in the management of women diagnosed with ADH on CNB, to minimize diagnostic excisional biopsies.

Atypical ductal hyperplasia: Our experience in the management and long term clinical follow-up in 71 patients

INTRODUCTION

Atypical ductal hyperplasia (ADH) is a high-risk benign lesion found in approximately 1-10% of breast biopsies and associated with a variable incidence of carcinoma after surgical excision. The main goal of our study is to present our experience in the management and long-term follow-up of 71 patients with ADH diagnosed on breast biopsy.

MATERIALS AND METHODS

Results of 3808 breast biopsy specimens from 1 January 2000 to 31 December 2005 were analyzed to identify all biopsies which resulted in a diagnosis of ADH. The histopathological results of the 45 patients who underwent surgery were analyzed. Long-term follow-up for the remaining patients was carried out.

RESULTS

45 of 71 (63.4%) patients with histological diagnosis of ADH on breast biopsy underwent surgery. Definitive histological results revealed invasive carcinoma in 7 cases (15.6%), high grade Ductal Carcinoma in situ (DCIS) in 10 (22.2%) patients, Lobular Carcinoma in situ (LCIS) in 4 cases (8.9%) and benign findings in 24 cases (53.3%). 12 of 71 (16.9%) patients underwent only long term follow-up; one (8,3%) of these developed invasive breast carcinoma after 6 years.

CONCLUSION

Atypical ductal hyperplasia diagnosed on breast biopsy is associated with a relatively high incidence of invasive carcinoma and high grade ductal carcinoma in situ at the time of surgical excision. Certain radiological and cytological criteria can be used to help determine which patients should forgo surgery and be followed up with good results. Long term follow-up is always crucial for patients who have not undergone surgery.