Mammography of ductal carcinoma in situ of the breast: review of 909 cases with radiographic-pathologic correlations

Update on Management of Ductal Carcinoma in Situ

Ductal carcinoma in situ (DCIS) represents 18% to 25% of all diagnosed breast cancers, and is a noninvasive, nonobligate precursor lesion to invasive cancer. The diagnosis of DCIS represents a wide range of disease, including lesions with both low and high risk of progression to invasive cancer and recurrence. Over the past decade, research on the topic of DCIS has focused on the possibility of tailoring treatment for patients according to their risk for progression and recurrence, which is based on clinicopathologic, biomolecular and genetic factors. These efforts are ongoing, with recently completed and continuing clinical trials spanning the continuum of cancer care. We conducted a review to identify recent advances on the topic of diagnosis, risk stratification and management of DCIS. While novel imaging techniques have increased the rate of DCIS diagnosis, questions persist regarding the optimal management of lesions that would not be identified with conventional methods. Additionally, among trials investigating the potential for omission of surgery and use of active surveillance, 2 trials have completed accrual and 2 clinical trials are continuing to enroll patients. Identification of novel genetic patterns is expanding our potential for risk stratification and aiding our ability to de-escalate radiation and systemic therapies for DCIS. These advances provide hope for tailoring of DCIS treatment in the near future.

Application of deep learning on mammographies to discriminate between low and high-risk DCIS for patient participation in active surveillance trials

BACKGROUND

Ductal Carcinoma In Situ (DCIS) can progress to invasive breast cancer, but most DCIS lesions never will. Therefore, four clinical trials (COMET, LORIS, LORETTA, AND LORD) test whether active surveillance for women with low-risk Ductal carcinoma In Situ is safe (E. S. Hwang et al., BMJ Open, 9: e026797, 2019, A. Francis et al., Eur J Cancer. 51: 2296-2303, 2015, Chizuko Kanbayashi et al. The international collaboration of active surveillance trials for low-risk DCIS (LORIS, LORD, COMET, LORETTA),  L. E. Elshof et al., Eur J Cancer, 51, 1497-510, 2015). Low-risk is defined as grade I or II DCIS. Because DCIS grade is a major eligibility criteria in these trials, it would be very helpful to assess DCIS grade on mammography, informed by grade assessed on DCIS histopathology in pre-surgery biopsies, since surgery will not be performed on a significant number of patients participating in these trials.

OBJECTIVE

To assess the performance and clinical utility of a convolutional neural network (CNN) in discriminating high-risk (grade III) DCIS and/or Invasive Breast Cancer (IBC) from low-risk (grade I/II) DCIS based on mammographic features. We explored whether the CNN could be used as a decision support tool, from excluding high-risk patients for active surveillance.

METHODS

In this single centre retrospective study, 464 patients diagnosed with DCIS based on pre-surgery biopsy between 2000 and 2014 were included. The collection of mammography images was partitioned on a patient-level into two subsets, one for training containing 80% of cases (371 cases, 681 images) and 20% (93 cases, 173 images) for testing. A deep learning model based on the U-Net CNN was trained and validated on 681 two-dimensional mammograms. Classification performance was assessed with the Area Under the Curve (AUC) receiver operating characteristic and predictive values on the test set for predicting high risk DCIS-and high-risk DCIS and/ or IBC from low-risk DCIS.

RESULTS

When classifying DCIS as high-risk, the deep learning network achieved a Positive Predictive Value (PPV) of 0.40, Negative Predictive Value (NPV) of 0.91 and an AUC of 0.72 on the test dataset. For distinguishing high-risk and/or upstaged DCIS (occult invasive breast cancer) from low-risk DCIS a PPV of 0.80, a NPV of 0.84 and an AUC of 0.76 were achieved.

CONCLUSION

For both scenarios (DCIS grade I/II vs. III, DCIS grade I/II vs. III and/or IBC) AUCs were high, 0.72 and 0.76, respectively, concluding that our convolutional neural network can discriminate low-grade from high-grade DCIS.

Clinicopathological and prognostic value of calcification morphology descriptors in ductal carcinoma in situ of the breast: a systematic review and meta-analysis

BACKGROUND

Calcifications on mammography can be indicative of breast cancer, but the prognostic value of their appearance remains unclear. This systematic review and meta-analysis aimed to evaluate the association between mammographic calcification morphology descriptors (CMDs) and clinicopathological factors.

METHODS

A comprehensive literature search in Medline via Ovid, Embase.com, and Web of Science was conducted for articles published between 2000 and January 2022 that assessed the relationship between CMDs and clinicopathological factors, excluding case reports and review articles. The risk of bias and overall quality of evidence were evaluated using the QUIPS tool and GRADE. A random-effects model was used to synthesize the extracted data. This systematic review is reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA).

RESULTS

Among the 4715 articles reviewed, 29 met the inclusion criteria, reporting on 17 different clinicopathological factors in relation to CMDs. Heterogeneity between studies was present and the overall risk of bias was high, primarily due to small, inadequately described study populations. Meta-analysis demonstrated significant associations between fine linear calcifications and high-grade DCIS [pooled odds ratio (pOR), 4.92; 95% confidence interval (CI), 2.64-9.17], (comedo)necrosis (pOR, 3.46; 95% CI, 1.29-9.30), (micro)invasion (pOR, 1.53; 95% CI, 1.03-2.27), and a negative association with estrogen receptor positivity (pOR, 0.33; 95% CI, 0.12-0.89).

CONCLUSIONS

CMDs detected on mammography have prognostic value, but there is a high level of bias and variability between current studies. In order for CMDs to achieve clinical utility, standardization in reporting of CMDs is necessary.

CRITICAL RELEVANCE STATEMENT

Mammographic calcification morphology descriptors (CMDs) have prognostic value, but in order for CMDs to achieve clinical utility, standardization in reporting of CMDs is necessary.

SYSTEMATIC REVIEW REGISTRATION

CRD42022341599 KEY POINTS: • Mammographic calcifications can be indicative of breast cancer. • The prognostic value of mammographic calcifications is still unclear. • Specific mammographic calcification morphologies are related to lesion aggressiveness. • Variability between studies necessitates standardization in calcification evaluation to achieve clinical utility.

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 findings for response evaluation of ductal carcinoma in situ in breast cancer patients treated with neoadjuvant systemic therapy: a systematic review and meta-analysis

OBJECTIVES

In approximately 45% of invasive breast cancer (IBC) patients treated with neoadjuvant systemic therapy (NST), ductal carcinoma in situ (DCIS) is present. Recent studies suggest response of DCIS to NST. The aim of this systematic review and meta-analysis was to summarise and examine the current literature on imaging findings for different imaging modalities evaluating DCIS response to NST. More specifically, imaging findings of DCIS pre- and post-NST, and the effect of different pathological complete response (pCR) definitions, will be evaluated on mammography, breast MRI, and contrast-enhanced mammography (CEM).

METHODS

PubMed and Embase databases were searched for studies investigating NST response of IBC, including information on DCIS. Imaging findings and response evaluation of DCIS were assessed for mammography, breast MRI, and CEM. A meta-analysis was conducted per imaging modality to calculate pooled sensitivity and specificity for detecting residual disease between pCR definition no residual invasive disease (ypT0/is) and no residual invasive or in situ disease (ypT0).

RESULTS

Thirty-one studies were included. Calcifications on mammography are related to DCIS, but can persist despite complete response of DCIS. In 20 breast MRI studies, an average of 57% of residual DCIS showed enhancement. A meta-analysis of 17 breast MRI studies confirmed higher pooled sensitivity (0.86 versus 0.82) and lower pooled specificity (0.61 versus 0.68) for detection of residual disease when DCIS is considered pCR (ypT0/is). Three CEM studies suggest the potential benefit of simultaneous evaluation of calcifications and enhancement.

CONCLUSIONS AND CLINICAL RELEVANCE

Calcifications on mammography can remain despite complete response of DCIS, and residual DCIS does not always show enhancement on breast MRI and CEM. Moreover, pCR definition effects diagnostic performance of breast MRI. Given the lack of evidence on imaging findings of response of the DCIS component to NST, further research is demanded.

KEY POINTS

• Ductal carcinoma in situ has shown to be responsive to neoadjuvant systemic therapy, but imaging studies mainly focus on response of the invasive tumour. • The 31 included studies demonstrate that after neoadjuvant systemic therapy, calcifications on mammography can remain despite complete response of DCIS and residual DCIS does not always show enhancement on MRI and contrast-enhanced mammography. • The definition of pCR has impact on the diagnostic performance of MRI in detecting residual disease, and when DCIS is considered pCR, pooled sensitivity was slightly higher and pooled specificity slightly lower.

Molecular Signatures in Ductal Carcinoma In Situ (DCIS): A Systematic Review and Meta-Analysis

CONTEXT

Adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) is debated as benefits are inconstant. Molecular signatures for DCIS have been developed to stratify the risk of local recurrence (LR) and therefore guide the decision of RT.

OBJECTIVE

To evaluate, in women with DCIS treated by BCS, the impact of adjuvant RT on LR according to the molecular signature risk stratification.

METHODOLOGY

We conducted a systematic review and meta-analysis of five articles including women with DCIS treated by BCS and with a molecular assay performed to stratify the risk, comparing the effect of BCS and RT versus BCS alone on LR including ipsilateral invasive (InvBE) and total breast events (TotBE).

RESULTS

The meta-analysis included 3478 women and evaluated two molecular signatures: Oncotype Dx DCIS (prognostic of LR), and DCISionRT (prognostic of LR and predictive of RT benefit). For DCISionRT, in the high-risk group, the pooled hazard ratio of BCS + RT versus BCS was 0.39 (95%CI 0.20-0.77) for InvBE and 0.34 (95%CI 0.22-0.52) for TotBE. In the low-risk group, the pooled hazard ratio of BCS + RT versus BCS was significant for TotBE at 0.62 (95%CI 0.39-0.99); however, it was not significant for InvBE (HR = 0.58 (95%CI 0.25-1.32)), Discussion: Molecular signatures are able to discriminate high- and low-risk women, high-risk ones having a significant benefit of RT in the reduction of invasive and in situ local recurrences, while in low-risk ones RT did not have a benefit for preventing invasive breast recurrence. The risk prediction of molecular signatures is independent of other risk stratification tools developed in DCIS, and have a tendency toward RT de-escalation. Further studies are needed to assess the impact on mortality.

Reoperation rate of ductal carcinoma in situ: impact of tomosynthesis (3D) and spot magnification

BACKGROUND

Surgical planning depends on precise preoperative assessment of the radiological extent of ductal carcinoma in situ (DCIS). Despite different modalities used, reoperation rates for DCIS due to involved margins are high.

PURPOSE

To evaluate the impact of additional imaging views (spot magnification, tomosynthesis) on surgical reoperation rate of DCIS.

MATERIAL AND METHODS

The retrospective single institute study includes 157 patients with biopsy-proven pure DCIS seen on mammogram as microcalcifications and treated with breast-conserving surgery. Patients have been divided into three groups according to additional imaging performed: spot magnification, tomosynthesis, and none. All breast images (mammograms, spot magnification, tomosynthesis) were reviewed and the maximum extent of pathological microcalcifications was recorded. Radiological size was compared to final histopathological size. Reoperation rate due to inadequate margins was recorded.

RESULTS

Reoperation rates (25%) due to inadequate margins were as follows: spot (18%), tomosynthesis (27%), none (31%); P = 0.488. Spot magnification, tomosynthesis, and digital zoom of full-field digital mammography predicted similarly the final histopathological size. Reoperation group had a significantly greater preoperative radiological median size (26 mm vs. 20 mm; P = 0.014) as well as median size of disease on final histopathological report (29 mm vs. 14 mm; P < 0.001). Discrepancy between radiological and final histopathological size became greater with increasing DCIS extent.

CONCLUSION

The main factors for reoperations are DCIS size and discordance between radiological and histopathological sizes. The use of additional imaging views (spot magnification, tomosynthesis) did not reduce reoperation rate.

Identifying recurrences and metastasis after ductal carcinoma in situ (DCIS) of the breast

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive tumour that has the potential to progress to invasive ductal carcinoma (IDC). Thus, it represents a treatment dilemma: alone it does not present a risk to life, however, left untreated it may progress to a life-threatening condition. Current clinico-pathological features cannot accurately predict which patients with DCIS have invasive potential, and therefore clinicians are unable to quantify the risk of progression for an individual patient. This leads to many women being over-treated, while others may not receive sufficient treatment to prevent invasive recurrence. A better understanding of the molecular features of DCIS, both tumour-intrinsic and the microenvironment, could offer the ability to better predict which women need aggressive treatment, and which can avoid therapies carrying significant side-effects and such as radiotherapy. In this review, we summarise the current knowledge of DCIS, and consider future research directions.

ACR Appropriateness Criteria® Evaluation of Nipple Discharge: 2022 Update

The type of nipple discharge dictates the appropriate imaging study. Physiologic nipple discharge is common and does not require diagnostic imaging. Pathologic nipple discharge in women, men, and transgender patients necessitates breast imaging. Evidence-based guidelines were used to evaluate breast imaging modalities for appropriateness based on patient age and gender. For an adult female or male 40 years of age or greater, mammography or digital breast tomosynthesis (DBT) is performed initially. Breast ultrasound is usually performed at the same time with rare exception. For males or females 30 to 39 years of age, mammography/DBT or breast ultrasound is performed based on institutional preference and individual patient considerations. For young women less than 30 years of age, ultrasound is performed first with mammography/DBT added if there are suspicious findings or if the patient is at elevated lifetime risk for developing breast cancer. There is a high incidence of breast cancer in males with pathologic discharge. Men 25 years and older should be evaluated using mammography/DBT and ultrasound added when indicted. In transfeminine (male-to-female) patients, mammography/DBT and ultrasound are useful due to the increased incidence of breast cancer. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Calcification, Posterior Acoustic, and Blood Flow: Ultrasonic Characteristics of Triple-Negative Breast Cancer

Previous studies suggest that triple-negative breast cancer (TNBC) may have unique imaging characteristics, however, studies focused on the imaging characteristics of TNBC are still limited. The aim of the present study is to analyze the ultrasonic characteristics of TNBC and to provide more reliable information on imaging diagnosis of TNBC. This retrospective study was performed including 162 TNBC patients with 184 TNBC lesions. 174 non-TNBC cases with 196 lesions were used as the control group. The median size of TNBC lesions and non-TNBC lesions were 23 mm × 16 mm and 21 mm × 15 mm, respectively. The shape of most breast cancer lesions was irregular. However, 15.30% (28/183) TNBC lesions and 16.84% (33/196) non-TNBC lesions were oval-shaped. Most breast cancer lesions (79.78% TNBC & 85.71% non-TNBC) were ill-defined. In comparison to non-TNBC, the distinctive ultrasonic characteristics of TNBC were summarized as three features: calcifications, posterior acoustic, and blood flow. Microcalcifications was less common in non-TNBC. The remarkable posterior acoustic characteristics on TNBC were no posterior acoustic features (136, 73.91%). Avascular pattern (21.74%) was also more common in TNBC. The other feature of TNBC was markedly hypoechoic lesions (23.91%). The above-mentioned differences between TNBC and non-TNBC were significant. 93.48% TBNC and 94.39% non–TNBC lesions were in BI-RADS-US category of 4A-5. The results indicate that TNBC has some distinctive ultrasound characteristics. Ultrasound is a useful adjunct in early detection of breast cancer. A combination of ultrasound with mammography is excellent for detecting breast cancer.

The Ultrasonographic Characteristics of Focal Fibrocystic Change of the Breast and Analysis of Misdiagnosis

INTRODUCTION

To investigate ultrasonographic features and analyze causes of misdiagnosis of focal fibrocystic change (FC) of the breast.

MATERIALS AND METHODS

The ultrasonographic features of 95 women (104 lesions) with postoperatively pathologically confirmed focal FC (Group 1) were retrospectively analyzed and compared with those of 105 women (107 lesions) with ductal carcinoma in situ (DCIS) (Group 2), and 164 women (177 lesions) with invasive ductal carcinoma (IDC) (Group 3).

RESULTS

There were significant differences in 12 features among groups. The sizes and distributions of cystic changes among the groups were significantly different. In group 1, the incidence of cystic changes was 75%(78/104), and the main manifestation was scattered cystic changes (88.5%, 69/78) and microcapsules (81.8%, 63/78). Among focal FC lesions, 36.5% were preoperative BI-RADS classifications 4b-5 (30.8% 4b and 4c). Lesions misdiagnosed as malignant showed solid or cystic solid mixed echoes, and 70.2% of group 1 were irregularly shaped, and 63.5% had unclear edges. In group 1, 5 cases had "hyperechoic halo," 11.5% (12/104) appeared echo attenuation behind the mass, and 21 cases appeared punctate hyperechoic.

CONCLUSION

FC frequently exhibits low heterogeneity, scattered microcapsules with posterior enhancement, "pit-like" or "grid-like" changes, posterior enhancement, rare hyperechoic halo, calcification, and lack of blood supply. Certain focal FC are irregularly shaped with unclear edges, with malignant signs such as crab feet and burr, hyperechoic halo, and calcification, which ultrasound BI-RADS classification may easily misdiagnose as malignant. Local magnification function should be considered, and the internal structure should be carefully observed to prevent misdiagnosis.

Breast cancer incidence by age at discovery of mammographic abnormality in women participating in French organized screening campaigns

OBJECTIVE

Statistical modeling was already predicted the occurrence/prognosis of breast cancer from previous radiological findings. This study predicts the breast cancer risk by the age at discovery of mammographic abnormality in the French breast cancer screening program.

STUDY DESIGN

This was a cohort study.

METHODS

The study included 261,083 women who meet the inclusion criteria: aged 50-74 years, living in French departments (Ain, Doubs, Haute-Saône, Jura, Territoire-de-Belfort, and Yonne), with at least two mammograms between January 1999 and December 2017, of which the first was 'normal/benign'. The incidence of each abnormality (microcalcifications, spiculated mass, obscured mass, architectural distortion, and asymmetric density) was first estimated, then the breast cancer risk was predicted secondly according to the age at discovery of each mammographic abnormality, using an actuarial life table and a Cox model.

RESULTS

Overall breast cancer (6326 cases) incidence was 3.3 (3.0; 3.1)/1000 person-years. The breast cancer incidence increased proportionally with the discovery age of the speculated mass and microcalcifications. The incidence was twice as high when the spiculated mass age of discovery was ≥70 (12.2 [10.4; 14.4]) compared with age 50-54 years (5.8 [5.1; 6.7]). Depending on the spiculated mass discovery age, the breast cancer risk increased by at least 40% between the age groups 55-59 years (1.4 [1.0; 1.8]) and ≥70 years (2.4 [1.9; 3.3]). Whatever the abnormality, the incidence of breast cancer was higher when it was present in only one breast.

CONCLUSION

The study highlights a stable incidence of breast cancer between successive mammograms, an increased risk of breast cancer with the finding age of spiculated mass and microcalcifications. The reduced delay between the abnormality discovery date and the breast cancer diagnosis date would justify a specific follow-up protocol after the finding of these two abnormalities.

Ductal Carcinoma in Situ: State-of-the-Art Review

Ductal carcinoma in situ (DCIS) is a nonobligate precursor of invasive cancer, and its detection, diagnosis, and management are controversial. DCIS incidence grew with the expansion of screening mammography programs in the 1980s and 1990s, and DCIS is viewed as a major driver of overdiagnosis and overtreatment. For pathologists, the diagnosis and classification of DCIS is challenging due to undersampling and interobserver variability. Understanding the progression from normal breast tissue to DCIS and, ultimately, to invasive cancer is limited by a paucity of natural history data with multiple proposed evolutionary models of DCIS initiation and progression. Although radiologists are familiar with the classic presentation of DCIS as asymptomatic calcifications at mammography, the expanded pool of modalities, advanced imaging techniques, and image analytics have identified multiple potential biomarkers of histopathologic characteristics and prognosis. Finally, there is growing interest in the nonsurgical management of DCIS, including active surveillance, to reduce overtreatment and provide patients with more personalized management options. However, current biomarkers are not adept at enabling identification of occult invasive disease at biopsy or accurately predicting the risk of progression to invasive disease. Several active surveillance trials are ongoing and are expected to better identify women with low-risk DCIS who may avoid surgery.

Significance of Removing Comedonecrosis as an Exclusion Criterion in Mammary Low-Risk Ductal Carcinoma In Situ Managed in an Active Surveillance Clinical Trial

OBJECTIVES

This study aims to investigate the consequences of comedonecrosis omission as an exclusion criterion of the Comparison of Operative vs Monitoring and Endocrine Therapy (COMET) trial.

METHODS

The clinical inclusion criteria of the COMET trial were applied on women who were mammographically screened between 2007 and 2017 and had a diagnosis of low- or intermediate-grade ductal carcinoma in situ (DCIS). The percentage of ductal diameter occupied by necrosis was calculated.

RESULTS

Twenty-six of 129 (20.2%) cases were upgraded. Larger calcification span correlated with upgrade (P = .02), with the best cutoff of 1.1 cm, and negative predictive value of 86%. When solely analyzing cases with no comedonecrosis (n = 76), none of the variables correlated with upgrade. Comedonecrosis was significantly correlated with upgrade to invasive carcinoma (P = .041), with the best cutoff of 53% of ductal diameter occupied by necrosis.

CONCLUSIONS

Results indicate that comedonecrosis and span of mammographic calcifications could be risk factors in women managed with active surveillance.

Contrast-Enhanced Mammographic Features of In Situ and Invasive Ductal Carcinoma Manifesting Microcalcifications Only: Help to Predict Underestimation?

BACKGROUND

The contrast-enhanced mammographic features of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) manifesting microcalcifications only on mammograms were evaluated to determine whether they could predict IDC underestimation.

METHODS

We reviewed patients who underwent mammography-guided biopsy on suspicious breast microcalcifications only and received contrast-enhanced spectral mammography (CESM) within 2 weeks before the biopsy. Those patients who were proven to have cancers (DCIS or IDC) by biopsy and subsequently had surgical treatment in our hospital were included for analysis. The presence or absence, size, morphology and texture of enhancement on contrast-enhanced spectral mammography were reviewed by consensus of two radiologists.

RESULTS

A total of 49 patients were included for analysis. Forty patients (81.6%) showed enhancement, including 18 (45%) DCIS and 22 (55%) IDC patients. All nine unenhanced cancers were pure DCIS. Pure DCIS showed 72.22% nonmass enhancement and 83.33% pure ground glass enhancement. IDC showed more mass (72.2% vs. 27.8%) and solid enhancements (83.33% vs. 16.67%). The cancer and texture of enhancement were significantly different between pure DCIS and IDC, with moderate diagnostic performance for the former (p-value < 0.01, AUC = 0.66, sensitivity = 93%, specificity = 39%) and the latter (p-value < 0.01, AUC = 0.74, sensitivity = 65%, specificity = 83%). Otherwise, pure DCIS showed a significant difference in enhanced texture compared with upgraded IDC and IDC (p = 0.0226 and 0.0018, respectively).

CONCLUSIONS

Nonmass and pure ground glass enhancements were closely related to pure DCIS, and cases showing mass and unpurified solid enhancements should be suspected as IDC. Unenhanced DCIS with microcalcifications only has a low DCIS upgrade rate. The CESM-enhanced features could feasibly predict IDC underestimation.

Magnetic Seed Localization (Magseed) for excision of impalpable breast lesions-The North Wales experience

The breast surgical community has faced huge challenges due to close working relationships with radiologists who are in short supply. Breast lesion localization is moving away from the traditional wire technique, which requires an on-site radiologist to support theater scheduling. In North Wales, the introduction of Magseed for impalpable breast lesion localization has facilitated theater scheduling in the absence of same day radiology presence. We audited our first 200 Magseed cases to assess the safety and efficacy of the technique, the ease of use, and patient experience. Data were entered prospectively into an excel data base relating to Magseed cases. Data collected included demographics, pre and postoperative lesion size, histology, margin positivity, and re-excision rates. Data were submitted in real time by the radiologist performing Magseed insertion to ascertain degree of difficulty. A PROMS questionnaire was designed and sent to patients undergoing Magseed vs wire localizations. Two hundred patients underwent Magseed-guided wide local excision between May 2018 and January 2020 across 2 district general hospital sites in North Wales. Histology: 69% IDC, 20% ILC, and 11% others. Mean preoperative size 12.3 mm, postoperative size 19 mm. Re-excision rate 15%. Re-excision for DCIS was significantly more likely than for invasive disease (p < 0.0001). A significant difference was also observed between radiological mean preoperative tumor size estimate and actual histological tumor size in patients undergoing margin re-excision (p = 0.000019). Wire-guided re-excision rate was 21% in the same unit. PROMs found the procedure well tolerated by patients. Surgeons and radiologists reported Magseed to be user-friendly with minimal learning curve. Magseed use for impalpable breast lesion localization is safe, user friendly, and well tolerated by patients. It produces favorable re-excision rates when compared to published figures for wire-guided excision. The presence of DCIS and preoperative radiological size underestimation was associated with margin re-excision.

Breast Cancer Staging: Updates in the AJCC Cancer Staging Manual, 8th Edition, and Current Challenges for Radiologists, From the AJR Special Series on Cancer Staging

The standardization of the AJCC TNM staging system for breast cancer allows physicians to evaluate patients with breast cancer using standard language and criteria, assess treatment response, and compare patient outcomes. Previous editions of the AJCC Cancer Staging Manual relied on the anatomic TNM method of staging that incorporates imaging and uses population-level survival data to predict patient outcomes. Recent advances in therapy based on biomarker status and multigene panels have improved treatment strategies. In the newest edition of the AJCC Cancer Staging Manual (8th edition, adopted on January 1, 2018), breast cancer staging integrates anatomic staging with tumor grade, biomarker data regarding hormone receptor status, oncogene expression, and gene expression profiling to assign a prognostic stage. This article reviews the 8th edition of the AJCC breast cancer staging system with a focus on anatomic staging and the challenges that anatomic staging poses for radiologists. We highlight key imaging findings that impact patient treatment and discuss the role of imaging in evaluating response to neoadjuvant therapy. Finally, we discuss biomarkers and multigene panels and how these impact prognostic stage. The review will help radiologists identify critical findings that affect breast cancer staging and understand ongoing limitations of imaging in staging.

Magnetic resonance imaging in the evaluation of pathologic nipple discharge: indications and imaging findings

Pathologic nipple discharge (PND) is typically unilateral, spontaneous, involves a single duct, and is serous or bloody in appearance. In patients with PND, breast MRI can be helpful as an additional diagnostic tool when conventional imaging with mammogram and ultrasound are negative. MRI is able to detect the etiology of nipple discharge in 56-61% of cases when initial imaging with mammogram and ultrasound are negative. Advantages to using MRI in evaluation of PND include good visualization of the retroareolar breast and better evaluation of posterior lesions which may not be well evaluated on mammograms and galactograms. It is also less invasive compared to central duct excision. Papillomas and nipple adenomas are benign breast masses that can cause PND and are well visualized on MRI. Ductal ectasia, and infectious etiologies such as mastitis, abscess, and fistulas are additional benign causes of PND that are well evaluated with MRI. MRI is also excellent for evaluation of malignant causes of PND including Paget's disease, ductal carcinoma in-situ and invasive carcinoma. MRI's high negative predictive value of 87-98.2% is helpful in excluding malignant etiologies of PND.

Ultrasound evaluation of ductal carcinoma in situ of the breast

PURPOSE

To assess the role of ultrasound (US) in detecting and characterizing ductal carcinoma in situ (DCIS) of the breast and to investigate the correlation between ultrasonographic and biological features of DCIS.

METHODS

In total, 171 patients (mean age 44; range 39-62) with 178 lesions were retrospectively evaluated by two independent radiologists searching for US mass or non-mass lesions. Immunohistochemistry analysis was performed to determine estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression. The US detection rate and pattern distribution among the lesion types were evaluated. The χ² test was used to evaluate the correlation between the US findings and the biological factors. Statistical significance was indicated by p values < 0.05. Inter-observer agreement was calculated by Kohen's k test.

RESULTS

US detected 35% (63/178) of all lesions. Fifty-two (83%) lesions were classified as mass lesions, and 11 (17%) as non-mass lesions (p < 0.0001). Among the mass lesions, the most common shape was irregular (79%; p < 0.0001), with 45 (87%) lesions having indistinct margins. Hypoechogenicity was the most common echo pattern (49 cases, 94%; p < 0.0001). Microcalcifications were found in 23 cases (37%; p = 0.004) and were associated with mass lesions in 15 cases (65%) and with non-mass lesions in 8 cases (35%) (p = 0.21). An almost perfect inter-observer agreement (k = 0.87) was obtained between the two radiologists. A significant ER expression was found in mass lesions (83%; p < 0.0001), with no significant PR (p = 0.89) or HER2 expression (p = 0.81). Among the lesions with microcalcifications, only 7 out of 23 cases (30%) were positive for HER2 (p = 0.09).

CONCLUSION

DCIS represents a heterogeneous pathological process with variable US appearance (mass-like, non-mass-like, or occult). The most common US finding is represented by mass-type, hypoechogenic lesions with indistinct margins. A significant ER expression exists among mass-type lesions, while microcalcifications seem not to be associated with HER2 expression.

Nipple Discharge: Current Clinical and Imaging Evaluation

OBJECTIVE. Nipple discharge is a common complaint that is first evaluated with clinical assessment. Physiologic discharge does not require imaging other than routine screening mammography. Initial evaluation of pathologic nipple discharge involves mammography and ultrasound. evaluation of pathologic nipple discharge involves mammography and ultrasound. Because of its high sensitivity in detecting breast malignancy and its biopsy capability, MRI is increasingly used in lieu of ductography. CONCLUSION. The problem-solving algorithm for evaluating suspicious nipple discharge is evolving. When diagnostic imaging for evaluation of pathologic nipple discharge is negative, management is based on clinical suspicion. If additional imaging is warranted, MRI is preferred because of its increased sensitivity, specificity, and patient comfort. Although central duct excision is the current standard for evaluation of malignancy in patients with pathologic nipple discharge, studies suggest that, given the high negative predictive value of MRI, surveillance may be a reasonable alternative to surgery.

The role of MRI and clinicopathologic features in predicting the invasive component of biopsy-confirmed ductal carcinoma in situ

Background

The upgrade rate of biopsy-confirmed ductal carcinoma in situ (DCIS) to invasive carcinoma is up to 50% on final pathology. We investigated MRI and clinicopathologic predictors of the invasive components of DCIS diagnosed by preoperative biopsy and then compared MRI features between patients with DCIS, microinvasive ductal carcinoma (mIDC), and invasive ductal carcinoma (IDC) diagnosed on final pathology.

Methods

Two hundred and one patients with 206 biopsy-confirmed DCIS lesions were enrolled. MRI and clinicopathologic features were used to predict either mIDC or IDC via a cumulative logistic regression analysis. For the lesions detected on MRI, morphologic and kinetic analyses were performed using the Chi-square, Fisher’s exact, and Kruskal-Wallis tests.

Results

Of all the lesions, 112 (54.4%) were diagnosed as DCIS, 50 (24.3%) were upgraded to mIDC, and 44 (21.4%) to IDC. The detection on MRI as mass (Odds ratio (OR) = 8.84, 95% confidence interval (CI) = 1.05–74.04, P = 0.045) or non-mass enhancement (NME; OR = 11.17, 95% CI = 1.35–92.36, P = 0.025), negative progesterone receptor (PR; OR = 2.40, 95% CI = 1.29–4.44, P = 0.006), and high Ki-67 level (OR = 2.42, 95% CI = 1.30–4.50, P = 0.005) were significant independent predictors of histologic upgrade. On MRI, 87 (42.2%) lesions appeared as mass and 107 (51.9%) as NME. Irregularly shaped, not-circumscribed, heterogeneous, or rim-enhancing masses with intratumoral high signal intensity or peritumoral edema, clumped or clustered ring-enhancing NMEs, and high peak enhancement were significantly associated with histologic upgrade (P < 0.001).

Conclusion

MRI detection, negative PR, and high Ki-67 levels are associated with a histologic upgrade in patients with biopsy-confirmed DCIS. Suspicious MRI features are more frequent in such patients.

Multimodality approach to the nipple-areolar complex: a pictorial review and diagnostic algorithm

The anatomic and histologic characteristics of the nipple-areolar complex make this breast region special. The nipple-areolar complex can be affected by abnormal development and a wide spectrum of pathological conditions, many of which have unspecific clinical and radiological presentations that can present a challenge for radiologists. The nipple-areolar complex requires a specific imaging workup in which a multimodal approach is essential. Radiologists need to know the different imaging modalities used to study the nipple-areolar complex, as well as their advantages and limitations. It is essential to get acquainted with the acquisition technique for each modality and the spectrum of findings for the different conditions. This review describes and illustrates a combined clinical and radiological approach to evaluate the nipple-areolar complex, emphasizing the findings for the normal morphology, developmental abnormalities, and the most common benign and malignant diseases that can affect this region. We also present a diagnostic algorithm that enables a rapid, practical approach to diagnosing condition involving the nipple-areolar complex.

A ten-year, single-center experience: Concordance between breast core needle biopsy/vacuum-assisted biopsy and postoperative histopathology in B3 and B5a cases

Purpose

To determine the concordance rate between core needle biopsy/vacuum-assisted biopsy (CNB/VAB) and postoperative histopathology in B3 (lesions of uncertain malignant potential) and B5a (in situ) lesions found on mammograms or ultrasound.

Material and methods

2,029 consecutive biopsies performed over 10 years for patients who underwent mammograms or ultrasounds. For CNB 14G needle and for VAB 8G/10G needles were used. In all biopsies, we identified the age, BI-RADS®, histopathological biopsy results, B-category, nuclear grade for DCIS and postoperative histopathology results in B3 and B5a cases from the biopsy.

Results

The B-categories from CNB/VAB were as follows: B2 42.2 percent (n = 856), B3 4.5 percent (n = 91), B5a 5.7 percent (n = 115), and B5b 47.6 percent (n = 967). In the B3-category, 72/91 patients underwent surgical excision, with a concordance rate of 83.3 percent (n = 60/72) and a discordance rate of 16.7 percent (n = 12/72) to postoperative histopathology. From the discordant cases, 67.7 percent (n = 8/12) showed DCIS and 32.3 percent (n = 4/12) showed invasive breast cancer. The BIRADS of the discordant cases was 4b in 41.7 percent (n = 5/12) and 5 in 58.3 percent (n = 7/12). The PPVs for malignancy of B3 lesions were 0.21, with no statistical significance between subgroups. In the B5a-category, 101 of 115 patients underwent surgery in our hospital, with a concordance rate of 80.2 percent (n = 81/101) and a discordance rate of 19.8 percent (n = 20/101) to postoperative histopathology. From the discordant cases, 55 percent (n = 11/20) showed invasive breast carcinoma of no special type (NST).

Conclusion

Our concordance rate for B3 (83.3 percent) and B5a (80.2 percent) lesions in the biopsies to postoperative histopathology is matching to previously published literature. Surgical excision is our recommendation for lesions biopsied with a B3 category in the histopathology and a BIRADS category of (4b, 4c and 5). The PPVs for malignancy of B3 lesions showed no statistical significance between subgroups. Also, the nuclear grade of DCIS was not statistically significant in terms of upgrade into invasive breast cancer.

Surgical Outcomes for Ductal Carcinoma in Situ: Impact of Preoperative MRI

Background The role of preoperative MRI for predicting surgical outcomes in patients diagnosed with ductal carcinoma in situ (DCIS) remains uncertain. Purpose To investigate the associations between preoperative MRI and surgical outcomes in DCIS confirmed by using US-guided core-needle biopsy (CNB) and to evaluate clinical-pathologic variables associated with a benefit from MRI. Materials and Methods Women with DCIS confirmed by using US-guided CNB between January 2012 and December 2016 were included in this retrospective study. Propensity score matching using 18 confounding covariates was used to create matched groups with MRI and without MRI, and surgical outcomes were compared. Clinical-pathologic variables were evaluated to determine women who benefited from MRI. Results A total of 541 women (mean age ± standard deviation, 50 years ± 10) were evaluated. Among 430 women who underwent MRI, 67 additional lesions (16%) were depicted, with 25 (37%) of the 67 additional lesions being malignant. Fifty-seven (13%) of the 430 women had a change in surgical plan because of their MRI findings; the change was appropriate for 31 (54%) women. In matched groups, the MRI group was associated with lower odds of positive resection margin (odds ratio [OR], 0.39; 95% confidence interval [CI]: 0.16, 0.93; P = .03) and repeat surgery (OR, 0.33; 95% CI: 0.12, 0.92; P = .03) compared with the non-MRI group. There was no difference in likelihood of initial mastectomy (OR, 1.2; 95% CI: 0.7, 2.0; P = .59) and overall mastectomy (OR, 0.93; 95% CI: 0.5, 1.6; P = .79). In the MRI group, low nuclear grade (90% [28 of 31] vs 69% [275 of 399]; P = .01), progesterone receptor positivity (81% [25 of 31] vs 61% [244 of 399]; P = .03), and human epidermal growth factor receptor 2 negativity (90% [28 of 31] vs 68% [270 of 399]; P = .01) were associated with a benefit from MRI versus no MRI. Conclusion Preoperative MRI depicted additional malignancy and reduced positive surgical margins and repeat surgery for ductal carcinoma in situ confirmed at US-guided biopsy without a higher mastectomy rate. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Pinker in this issue.

Diffusion-weighted MRI for Unenhanced Breast Cancer Screening

Diffusion-weighted (DW) MRI is a rapid technique that measures the mobility of water molecules within tissue, reflecting the cellular microenvironment. At DW MRI, breast cancers typically exhibit reduced diffusivity and appear hyperintense to surrounding tissues. On the basis of this characteristic, DW MRI may offer an unenhanced method to detect breast cancer without the costs and safety concerns associated with dynamic contrast material-enhanced MRI, the current reference standard in the setting of high-risk screening. This application of DW MRI has not been widely explored but is particularly timely given the growing health concerns related to the long-term use of gadolinium-based contrast material. Moreover, increasing breast density notification legislation across the United States is raising awareness of the limitations of mammography in women with dense breasts, emphasizing the need for additional cost-effective supplemental screening examinations. Preliminary studies suggest unenhanced MRI with DW MRI may provide higher sensitivity than screening mammography for the detection of breast malignancies. Larger prospective multicenter trials are needed to validate single-center findings and assess the performance of DW MRI for generalized breast cancer screening. Standardization of DW MRI acquisition and interpretation is essential to ensure reliable sensitivity and specificity, and an optimal approach for screening using readily available techniques is proposed here.

Role of Breast MRI in the Evaluation and Detection of DCIS: Opportunities and Challenges

Historically, breast magnetic resonance imaging (MRI) was not considered an effective modality in the evaluation of ductal carcinoma in situ (DCIS). Over the past decade this has changed, with studies demonstrating that MRI is the most sensitive imaging tool for detection of all grades of DCIS. It has been suggested that not only is breast MRI the most sensitive imaging tool for detection but it may also detect the most clinically relevant DCIS lesions. The role and outcomes of MRI in the preoperative setting for patients with DCIS remains controversial; however, several studies have shown benefit in the preoperative evaluation of extent of disease as well as predicting an underlying invasive component. The most common presentation of DCIS on MRI is nonmass enhancement (NME) in a linear or segmental distribution pattern. Maximizing breast MRI spatial resolution is therefore beneficial, given the frequent presentation of DCIS as NME on MRI. Emerging MRI techniques, such as diffusion-weighted imaging (DWI), have shown promising potential to discriminate DCIS from benign and invasive lesions. Future opportunities including advanced imaging visual techniques, radiomics/radiogenomics, and machine learning / artificial intelligence may also be applicable to the detection and treatment of DCIS. Level of Evidence: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2020;52:697-709.

Ductal Carcinoma in Situ: Current Concepts in Biology, Imaging, and Treatment

Ductal carcinoma in situ (DCIS) of the breast is a group of heterogeneous epithelial proliferations confined to the milk ducts that nearly always present in asymptomatic women on breast cancer screening. A stage 0, preinvasive breast cancer, increased detection of DCIS was initially hailed as a means to prevent invasive breast cancer through surgical treatment with adjuvant radiation and/or endocrine therapies. However, controversy in the medical community has emerged in the past two decades that a fraction of DCIS represents overdiagnosis, leading to unnecessary treatments and resulting morbidity. The imaging hallmarks of DCIS include linearly or segmentally distributed calcifications on mammography or nonmass enhancement on breast MRI. Imaging features have been shown to reflect the biological heterogeneity of DCIS lesions, with recent studies indicating MRI may identify a greater fraction of higher-grade lesions than mammography does. There is strong interest in the surgical, imaging, and oncology communities to better align DCIS management with biology, which has resulted in trials of active surveillance and therapy that is less aggressive. However, risk stratification of DCIS remains imperfect, which has limited the development of precision therapy approaches matched to DCIS aggressiveness. Accordingly, there are opportunities for breast imaging radiologists to assist the oncology community by leveraging advanced imaging techniques to identify appropriate patients for the less aggressive DCIS treatments.

Ductal carcinoma in situ: to treat or not to treat, that is the question

Ductal carcinoma in situ (DCIS) now represents 20-25% of all 'breast cancers' consequent upon detection by population-based breast cancer screening programmes. Currently, all DCIS lesions are treated, and treatment comprises either mastectomy or breast-conserving surgery supplemented with radiotherapy. However, most DCIS lesions remain indolent. Difficulty in discerning harmless lesions from potentially invasive ones can lead to overtreatment of this condition in many patients. To counter overtreatment and to transform clinical practice, a global, comprehensive and multidisciplinary collaboration is required. Here we review the incidence of DCIS, the perception of risk for developing invasive breast cancer, the current treatment options and the known molecular aspects of progression. Further research is needed to gain new insights for improved diagnosis and management of DCIS, and this is integrated in the PRECISION (PREvent ductal Carcinoma In Situ Invasive Overtreatment Now) initiative. This international effort will seek to determine which DCISs require treatment and prevent the consequences of overtreatment on the lives of many women affected by DCIS.

New advance in breast cancer pathology and imaging

The improvement of knowledge concerning the pathology of breast cancer could provide the rationale for the development of new imaging diagnostic protocols. Indeed, as for the microcalcifications, new histopathological markers can be used as target for in vivo early detection of breast cancer lesions by using molecular imaging techniques such as positron emission tomography. Specifically, the mutual contribution of these medical specialties can ‘nourish’ the dream of a personalized medicine that takes into account the intrinsic variability of breast cancer. In this review, we report the main discoveries concerning breast cancer pathology highlighting the possible cooperation between the departments of anatomic pathology and imaging diagnostics.

US and MRI in the evaluation of mammographic BI-RADS 4 and 5 microcalcifications

PURPOSE

The aim of this study was to assess diagnostic accuracies of ultrasonography (US) and magnetic resonance imaging (MRI) in lesions that manifest as mammographic BI-RADS 4 and 5 microcalcifications, in the setting of conjoined use of mammography, US, and MRI.

METHODS

Patients with mammographic BI-RADS 4 or 5 microcalcifications, without additional findings, were included in this prospective study. All patients subsequently underwent breast US and MRI. Histopathologic diagnosis, obtained by US-guided core-needle biopsy or surgical excision, served as a reference standard. Diagnostic accuracies of US and MRI were calculated, and positive predictive value for different MRI BI-RADS imaging features were determined.

RESULTS

The study group consisted of 113 women with 125 areas of suspicious microcalcifications. MRI reached sensitivity, specificity, positive predictive value 3 (PPV3), and negative predictive value (NPV) of 100%, 70.1%, 67.6%, and 100%, respectively. Statistically significant differences in MRI morphologic features and kinetic enhancement curves were observed between malignant and benign microcalcifications. Sensitivity, specificity, PPV3, and NPV for US were: 85.4%, 66.2%, 61.2%, and 87.9%. There was statistically significant difference in presentation of malignant and benign microcalcifications at US.

CONCLUSION

In the setting of conjoined use of mammography, US, and MRI, MRI can reliably exclude malignancy in suspicious microcalcifications. Thus, negative MRI findings may influence the decision to biopsy the microcalcifications.

Factors affecting the concordance of radiologic and pathologic tumor size in breast carcinoma

Background

Radiologic assessment of tumor size is an integral part of the work-up for breast carcinoma. With improved radiologic equipment, surgical decision relies profoundly upon radiologic/clinical stage. We wanted to see the concordance between radiologic and pathologic tumor size to infer how accurate radiologic/clinical staging is.

Materials and methods

The surgical pathology and ultrasonography reports of patients with breast carcinoma were reviewed. Data were collected for 406 cases. Concordance was defined as a size difference within ±2 mm.

Results

The difference between radiologic and pathologic tumor size was within ±2 mm in 40.4% cases. The mean radiologic size was 1.73 ± 1.06 cm. The mean pathologic size was 1.84 ± 1.24 cm. A paired t-test showed a significant mean difference between radiologic and pathologic measurements (0.12 ± 1.03 cm, p = 0.03). Despite the size difference, stage classification was the same in 59.9% of cases. Radiologic size overestimated stage in 14.5% of cases and underestimated stage in 25.6% of cases. The concordance rate was significantly higher for tumors ≤2 cm (pT1) (51.1%) as compared to those greater than 2 cm (≥pT2) (19.7%) (p < 0.0001). Significantly more lumpectomy specimens (47.5%) had concordance when compared to mastectomy specimens (29.8%) (p < 0.0001). Invasive ductal carcinoma had better concordance compared to other tumors (p = 0.02).

Conclusion

Mean pathologic tumor size was significantly different from mean radiologic tumor size. Concordance was in just over 40% of cases and the stage classification was the same in about 60% of cases only. Therefore, surgical decision of lumpectomy versus mastectomy based on radiologic tumor size may not always be accurate.

Histopathology findings of non-mass cancers on breast ultrasound

Background

There is little research done on non-mass cancers (NMCs) on breast ultrasound (US).

Purpose

To evaluate large-sectional histopathology findings of NMCs on breast US.

Material and Methods

The mammographic and histopathology features of biopsy proven 36 breast cancers which showed pure non-mass lesions on US were retrospectively reviewed.

Results

The most common mammographic finding was microcalcification (23/35, 65.7%); fine pleomorphic microcalcification was predominant (18/23, 78.3%). The main tumor type was pure ductal carcinoma in situ (DCIS) (14/36, 38.9%) and DCIS with micro- or minimal invasion (11/36, 30.6%). Among the 25 DCIS, histologic grade was high in 15 (60.0%) and intermediate in nine (36%); comedo necrosis was seen in 17 (68%). Immunohistochemical analysis was available in 27 lesions and showed HER2-overexpression in 12 (44.4%) and triple-negative in two (7.4%).

Conclusion

According to our limited patient sample, NMCs on breast US were mainly associated with high-grade DCIS.

ACR Appropriateness Criteria® Evaluation of Nipple Discharge

Appropriate imaging evaluation of nipple discharge depends the nature of the discharge. Imaging is not indicated for women with physiologic nipple discharge. For evaluation of pathologic nipple discharge, multiple breast imaging modalities are rated for evidence-based appropriateness under various scenarios. For women age 40 or older, mammography or digital breast tomosynthesis (DBT) should be the initial examination. Ultrasound is usually added as a complementary examination, with some exceptions. For women age 30 to 39, either mammogram or ultrasound may be used as the initial examination on the basis of institutional preference. For women age 30 or younger, ultrasound should be the initial examination, with mammography/DBT added when ultrasound shows suspicious findings or if the patient is predisposed to developing breast cancer. For men age 25 or older, mammography/DBT should be performed initially, with ultrasound added as indicated, given the high incidence of breast cancer in men with pathologic nipple discharge. Although MRI and ductography are not usually appropriate as initial examinations, each may be useful when the initial standard imaging evaluation is negative. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Comparison of mammography, ultrasound, and MRI in size assessment of ductal carcinoma in situ with histopathologic correlation

Background The ability to accurately assess tumor size in ductal carcinoma in situ (DCIS) is an important clinical issue when selecting the appropriate treatment plan. Purpose To compare the accuracy of using mammography, ultrasound (US), and magnetic resonance imaging (MRI) to assess DCIS tumor size based on imaging and histopathological findings. Material and Methods Fifty-six patients with DCIS were included. Mammography, US, and MRI were reviewed, and the accuracy of the measured tumor sizes were compared with the imaging and histopathological parameters. Results If visible, tumor measurements demonstrated high reliability with the pathologically determined size, with the best results obtained using US ( k = 0.851) followed by mammography ( k = 0.815) and MRI ( k = 0.738). Tumor size assessment was significantly more accurate when the lesion was shown as a mass on US ( P = 0.003) or MRI ( P < 0.001) with minimal and mild background parenchymal enhancement ( P = 0.016) on MRI. When mammography was used to assess tumor size, the tumors with positive estrogen receptor status and luminal A subtype demonstrated a significantly more accurate tumor size. Conclusion The combination of US and MRI, in addition to mammography, has an important role in assessing the exact tumor extent of DCIS.

Imaging Features of Patients Undergoing Active Surveillance for Ductal Carcinoma in Situ

RATIONALE AND OBJECTIVES

The aim of this study was to describe the imaging appearance of patients undergoing active surveillance for ductal carcinoma in situ (DCIS).

MATERIALS AND METHODS

We retrospectively identified 29 patients undergoing active surveillance for DCIS from 2009 to 2014. Twenty-two patients (group 1) refused surgery or were not surgical candidates. Seven patients (group 2) enrolled in a trial of letrozole and deferred surgical excision for 6-12 months. Pathology and imaging results at the initial biopsy and follow-up were recorded.

RESULTS

In group 1, the median follow-up was 2.7 years (range: 0.6-13.9 years). Fifteen patients (68%) remained stable. Seven patients (32%) underwent additional biopsies with invasive ductal carcinoma diagnosed in two patients after 3.9 and 3.6 years who developed increasing calcifications and new masses. In group 2, one patient (14%) was upstaged to microinvasive ductal carcinoma at surgery. Among the patients in both groups with calcifications (n = 26), there was no progression to invasive disease among those with stable (50%, 13/26) or decreased (19%, 5/26) calcifications.

CONCLUSIONS

Among a DCIS active surveillance cohort, invasive disease progression presented as increasing calcifications and a new mass following more than 3.5 years of stable imaging. In contrast, there was no progression to invasive disease among cases of DCIS with stable or decreasing calcifications. Close imaging is a key follow-up component in active surveillance.

Can magnetic resonance imaging obviate the need for biopsy for microcalcifications?

BACKGROUND

Although microcalcifications detected with mammography (MG) are usually biopsied, biopsies cannot be performed in all cases. We sought to determine if magnetic resonance imaging (MRI) findings could indicate whether stereotactic vacuum-assisted biopsy (SVAB) is necessary.

METHODS

Patients with mammographically detected Breast Imaging-Reporting and Data System (BI-RADS) 3, 4, and 5 microcalcifications were analyzed from April 2012 to September 2014. All patients underwent MRI. All patients with enhancing lesions in the region of the microcalcifications underwent SVAB. Non-enhancing lesions were followed or biopsied, depending on the patient's preferences. MRI findings were classified as either malignant-suspicious or benign-suspicious ("none" or "nonspecific"), and we evaluated the positive predictive value (PPV) and negative predictive value (NPV) of these classifications for predicting malignancy.

RESULTS

A total of 87 patients underwent both MRI and SVAB. The NPV of MRI was 100% in the group with no enhancement. In BI-RADS category 3, there were 57 benign-suspicious lesions on MRI, of which eight were malignant (NPV of MRI: 85.0%).

CONCLUSIONS

It may be possible to omit SVAB for microcalcifications if there is no enhancement on MRI; however, any kind of enhancement indicates the need for biopsy in cases of BI-RADS 3 calcifications on MG.

Preoperative prediction of the size of pure ductal carcinoma in situ using three imaging modalities as compared to histopathological size: does magnetic resonance imaging add value?

PURPOSE

The purpose of this study was to evaluate whether magnetic resonance imaging (MRI) and ultrasonography add value to traditional mammography in an Asian population with ductal carcinoma in situ (DCIS).

METHODS

Data of 244 patients with pure DCIS treated at Severance Hospital between 2013 and 2015 were analyzed retrospectively. Data extracted included age, preoperative diagnosis, tumor size on preoperative imaging studies, and final histopathological tumor type and size, including hormone receptor status. The extent of correlation between imaging and histopathological tumor sizes was evaluated using a variety of methods, including Bland-Altman analysis.

RESULTS

The mean patient age was 52.39 years (SD = 10.31). The mean measurements of the tumor on preoperative ultrasonography, mammography, MRI, and histopathology were 1.80 (SD = 1.23) cm, 2.97 (SD = 1.92) cm, 2.53(SD = 1.84) cm, and 1.88 (SD = 1.36) cm, respectively. The mean differences in tumor size between ultrasonography, mammography, and MRI compared with histopathology were -0.09 (SD = 1.39), 1.09 (SD = 1.89), and 0.65 (SD = 1.78), respectively. The correlation between the sizes was significant with r values for ultrasonography, mammography, and MRI of 0.447 (SE = 0.061), 0.375 (SE = 0.042), and 0.409 (SE = 0.043), respectively. Mammography and MRI estimated tumor size significantly better for patients older than 50 years (p = 0.045 and <0.001, respectively). Mammography also provided good estimation for patients with a body mass index under 25 (p = 0.041).

CONCLUSION

MRI is better at estimation of histopathological DCIS size compared with mammography. However, ultrasonography had better estimation compared with MRI and mammography, probably owing to the high breast density in this population.

MRI in the differential diagnosis of primary architectural distortion detected by mammography

PURPOSE

We aimed to evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and apparent diffusion coefficient (ADC) values in lesions that manifest with architectural distortion (AD) on mammography.

METHODS

All full-field digital mammography (FFDM) images obtained between August 2010 and January 2013 were reviewed retrospectively, and 57 lesions showing AD were included in the study. Two independent radiologists reviewed all mammograms and MRI data and recorded lesion characteristics according to the BI-RADS lexicon. The gold standard was histopathologic results from biopsies or surgical excisions and results of the two-year follow-up. Receiver operating characteristic curve analysis was carried out to define the most effective threshold ADC value to differentiate malignant from benign breast lesions. We investigated the sensitivity and specificity of FFDM, DCE-MRI, FFDM+DCE-MRI, and DCE-MRI+ADC.

RESULTS

Of the 57 lesions analyzed, 28 were malignant and 29 were benign. The most effective threshold for the normalized ADC (nADC) was 0.61 with 93.1% sensitivity and 75.0% specificity. The sensitivity and specificity of DCE-MRI combined with nADC was 92.9% and 79.3%, respectively. DCE-MRI combined with nADC showed the highest specificity and equal sensitivity compared with other modalities, independent of the presentation of calcification.

CONCLUSION

DCE-MRI combined with nADC values was more reliable than mammography in differentiating the nature of disease manifesting as primary AD on mammography.

Ductal carcinoma in situ - update on risk assessment and management

Ductal carcinoma in situ (DCIS) accounts for ~20-25% of breast cancers. While DCIS is not life-threatening, it may progress to invasive carcinoma over time, and treatment intended to prevent invasive progression may itself cause significant morbidity. Accurate risk assessment is therefore necessary to avoid over- or undertreatment of an individual patient. In this review we will outline the evidence for current management of DCIS, discuss approaches to DCIS risk assessment and challenges facing identification of novel DCIS biomarkers.

Breast Cancer Detection in a Screening Population: Comparison of Digital Mammography, Computer-Aided Detection Applied to Digital Mammography and Breast Ultrasound

Purpose

We aimed to compare the detection of breast cancer using full-field digital mammography (FFDM), FFDM with computer-aided detection (FFDM+CAD), ultrasound (US), and FFDM+CAD plus US (FFDM+CAD+US), and to investigate the factors affecting cancer detection.

Methods

In this retrospective study conducted from 2008 to 2012, 48,251 women underwent FFDM and US for cancer screening. One hundred seventy-one breast cancers were detected: 115 invasive cancers and 56 carcinomas in situ. Two radiologists evaluated the imaging findings of FFDM, FFDM+CAD, and US, based on the Breast Imaging Reporting and Data System lexicon of the American College of Radiology by consensus. We reviewed the clinical and the pathological data to investigate factors affecting cancer detection. We statistically used generalized estimation equations with a logit link to compare the cancer detectability of different imaging modalities. To compare the various factors affecting detection versus nondetection, we used Wilcoxon rank sum, chi-square, or Fisher exact test.

Results

The detectability of breast cancer by US (96.5%) or FFDM+CAD+US (100%) was superior to that of FFDM (87.1%) (p=0.019 or p<0.001, respectively) or FFDM+ CAD (88.3%) (p=0.050 or p<0.001, respectively). However, cancer detectability was not significantly different between FFDM versus FFDM+CAD (p=1.000) and US alone versus FFDM+CAD+US (p=0.126). The tumor size influenced cancer detectability by all imaging modalities (p<0.050). In FFDM and FFDM+CAD, the nondetecting group consisted of younger patients and patients with a denser breast composition (p<0.050). In breast US, carcinoma in situ was more frequent in the nondetecting group (p=0.014).

Conclusion

For breast cancer screening, breast US alone is satisfactory for all age groups, although FFDM+ CAD+US is the perfect screening method. Patient age, breast composition, and pathological tumor size and type may influence cancer detection during screening.

Tumor characteristics of ductal carcinoma in situ of breast visualized on [F-18] fluorodeoxyglucose-positron emission tomography/computed tomography: Results from a retrospective study

AIM

To clarify clinicopathological features of ductal carcinoma in situ (DCIS) visualized on [F-18] fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT).

METHODS

This study retrospectively reviewed 52 consecutive tumors in 50 patients with pathologically proven pure DCIS who underwent [F-18] FDG-PET/CT before surgery. [F-18] FDG-PET/CT was performed after biopsy in all patients. The mean interval from biopsy to [F-18] FDG-PET/CT was 29.2 d. [F-18] FDG uptake by visual analysis and maximum standardized uptake value (SUVmax) was compared with clinicopathological characteristics.

RESULTS

[F-18] FDG uptake was visualized in 28 lesions (53.8%) and the mean and standard deviation of SUVmax was 1.63 and 0.90. On univariate analysis, visual analysis and the SUVmax were associated with symptomatic presentation (P = 0.012 and 0.002, respectively), palpability (P = 0.030 and 0.024, respectively), use of core-needle biopsy (CNB) (P = 0.023 and 0.012, respectively), ultrasound-guided biopsy (P = 0.040 and 0.006, respectively), enhancing lesion ≥ 20 mm on magnetic resonance imaging (MRI) (P = 0.001 and 0.010, respectively), tumor size ≥ 20 mm on histopathology (P = 0.002 and 0.008, respectively). However, [F-18] FDG uptake parameters were not significantly associated with age, presence of calcification on mammography, mass formation on MRI, presence of comedo necrosis, hormone status (estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2), and nuclear grade. The factors significantly associated with visual analysis and SUVmax were symptomatic presentation (P = 0.019 and 0.001, respectively), use of CNB (P = 0.001 and 0.031, respectively), and enhancing lesion ≥ 20 mm on MRI (P = 0.001 and 0.049, respectively) on multivariate analysis.

CONCLUSION

Although DCIS of breast is generally non-avid tumor, symptomatic and large tumors (≥ 20 mm) tend to be visualized on [F-18] FDG-PET/CT.