Improved malignancy prediction by B3 breast lesions subclassification

Malignancy Rate and Malignancy Risk Assessment in Different Lesions of Uncertain Malignant Potential in the Breast (B3 Lesions): An Analysis of 192 Cases from a Single Institution

BACKGROUND

The question of how to deal with B3 lesions is of emerging interest.

METHODS

In the breast diagnostics of 192 patients between 2009 and 2016, a minimally invasive biopsy revealed a B3 lesion with subsequent resection. This study investigates the malignancy rate of different B3 subgroups and the risk factors that play a role in obtaining a malignant finding.

RESULTS

The distribution of B3 lesions after minimally invasive biopsy was as follows: atypical ductal hyperplasia (ADH), 7.3%; flat epithelial atypia (FEA), 7.8%; lobular neoplasia (LN), 7.8%; papilloma (Pa), 49.5%; phylloidal tumour (PT), 8.9%; radial sclerosing scar (RS), 3.1%; mixed findings, 10.4%; and other B3 lesions, 5.2%. Most B3 lesions were detected by stereotactic vacuum-assisted biopsy (44.3%), 36.5% by ultrasound-assisted biopsy, and 19.3% by magnetic resonance imaging-assisted biopsy. Most B3 lesions (55.2%) were verified by surgical resection, whereas 30.7% were downgraded to a benign lesion. About 14.1% of the cases were upgraded to malignant lesions, 9.4% to ductal carcinoma in situ and 4.7% to invasive carcinoma. In relation to individual B3 lesions, the following malignancy rates were found: 28.6% (ADH), 13.3% (FEA), 33.3% (LN), 12.6% (Pa), 5.9% (PT), and 0% (RS). The most important risk factor was increasing age. Postmenopausal status was considered an increased risk for an upgrade (p = 0.015). A known malignancy in the ipsilateral breast was a significant risk factor for a malignant upgrade (p = 0.003).

CONCLUSION

Increasing knowledge about B3 lesions allows us to develop a "lesion-specific" therapy approach in the heterogeneous group of B3 lesions, with follow-up imaging for some lesions with less malignant potential and concordance with imaging or further surgical resection in cases of disconcordance with imaging or higher malignant potential.

B3 Lesions at Vacuum-Assisted Breast Biopsy under Ultrasound or Mammography Guidance: A Single-Center Experience on 3634 Consecutive Biopsies

The rate of upgrade to cancer for breast lesions with uncertain malignant potential (B3 lesions) diagnosed at needle biopsy is highly influenced by several factors, but large series are seldom available. We retrospectively assessed the upgrade rates of a consecutive series of B3 lesions diagnosed at ultrasound- or mammography-guided vacuum-assisted biopsy (VAB) at an EUSOMA-certified Breast Unit over a 7-year timeframe. The upgrade rate was defined as the number of ductal carcinoma in situ (DCIS) or invasive cancer at pathology after excision or during follow-up divided by the total number of B3 lesions. All lesions were reviewed by one of four pathologists with a second opinion for discordant assessments of borderline cases. Excision or surveillance were defined by the multidisciplinary tumor board, with 6- and 12-month follow-up. Out of 3634 VABs (63% ultrasound-guided), 604 (17%) yielded a B3 lesion. After excision, 17/604 B3 lesions were finally upgraded to malignancy (2.8%, 95% confidence interval [CI] 1.8-4.5%), 10/17 (59%) being upgraded to DCIS and 7/17 (41%) to invasive carcinoma. No cases were upgraded during follow-up. B3a lesions showed a significantly lower upgrade rate (0.4%, 95% CI 0.1-2.1%) than B3b lesions (4.7%, 95% CI 2.9-7.5%, p = 0.001), that had a 22.0 adjusted odds ratio for upgrade (95% CI 2.1-232.3). No significant difference was found in upgrade rates according to imaging guidance or needle caliper. Surveillance-oriented management can be considered for B3a lesions, while surgical excision should be pursued for B3b lesions.

Apparent diffusion coefficient values in borderline breast lesions upgraded and not upgraded at definitive histopathological examination after surgical excision

Purpose

The study aims were to evaluate if the apparent diffusion coefficient (ADC) value could distinguish between breast lesions classified as B3 at core needle biopsy (CNB) that show or do not show atypia or malignancy at definitive histopathological examination (DHE) after surgical excision.

Material and methods

From January 2013 to December 2017, 141 patients with a B3 breast lesion underwent magnetic resonance imaging and were included in the study. The ADC value was assessed drawing a ROI outlining the entire lesion, evaluating the mean (ADC_mean) and minimum ADC values (ADC_min).

Results

Both ADC_mean and ADC_min values showed a statistically significant difference between B3 lesions without and with malignancy or, for B3a lesions, atypia at DHE. They both showed a statistically significant difference also between B3a lesions without or with atypia or malignancy at DHE, but only ADC_min (not ADC_mean) showed statistically significant difference between B3b lesions without or with malignancy at DHE.

Conclusions

The ADC value could help distinguish between B3a lesions without or with atypia/malignancy at DHE after surgical excision and between B3b lesions without or with malignancy at DHE. Therefore, it could be used to help guide the diagnostic-therapeutic pathway of these lesions, particularly of B3a lesions.

Elite VABB 13G: A New Ultrasound-Guided Wireless Biopsy System for Breast Lesions. Technical Characteristics and Comparison with Respect to Traditional Core-Biopsy 14-16G Systems

The typification of breast lumps with fine-needle biopsies is often affected by inconclusive results that extend diagnostic time. Many breast centers have progressively substituted cytology with micro-histology. The aim of this study is to assess the performance of a 13G-needle biopsy using cable-free vacuum-assisted breast biopsy (VABB) technology. Two of our operators carried out 200 micro-histological biopsies using the Elite 13G-needle VABB and 1314 14–16G-needle core biopsies (CBs) on BI-RADS 3, 4, and 5 lesions. Thirty-one of the procedures were repeated following CB, eighteen following cytological biopsy, and three after undergoing both procedures. The VABB Elite procedure showed high diagnostic performance with an accuracy of 94.00%, a sensitivity of 92.30%, and a specificity of 100%, while the diagnostic underestimation was 11.00%, all significantly comparable to of the CB procedure. The VABB Elite 13G system has been shown to be a simple, rapid, reliable, and well-tolerated biopsy procedure, without any significant complications and with a diagnostic performance comparable to traditional CB procedures. The histological class change in an extremely high number of samples would suggest the use of this procedure as a second-line biopsy for suspect cases or those with indeterminate cyto-histological results.

External Validation of a Risk Stratification Score for B3 Breast Lesions Detected at Ultrasound Core Needle Biopsy

OBJECTIVE

The aim of this study was to externally validate the feasibility and robustness of a risk-stratification score for B3 lesions based on clinical, pathological, and radiological data for improved clinical decision making.

METHODS

129 consecutive histologically confirmed B3 lesions diagnosed at ultrasound-guided biopsy at our institution were included in this retrospective study. Patient- and lesion-related variables were independently assessed by two blinded breast radiologists (R1, R2), by assigning each feature a score from 0 to 2 (maximum sum-score of 5). Sensitivity, specificity, positive and negative predictive values were calculated at two different thresholds (≥1 and 2). Categorical variables were compared using Chi-squared and Fisher exact tests. The diagnostic accuracy of the score to distinguish benign from malignant B3 lesions was assessed by receiver operating characteristic (ROC) analysis.

RESULTS

Surgery was performed on 117/129 (90.6%) lesions and 11 of these 117 (9.4%) lesions were malignant. No cancers were found at follow-up of at least 24 months. Area under the ROC-curve was 0.736 (R1) to 0.747 (R2), with no significant difference between the two readers (p = 0.5015). Using a threshold of ≥1, a sensitivity, specificity, PPV, and NPV of 90%/90% (R1/R2), 39%/38% (R1/R2), 11%/12% (R1/R2) and 97%/98% (R1/R2) were identified. Both readers classified 47 lesions with a score ≤1 (low risk of associated malignancy). Of these, only one malignant lesion was underdiagnosed (Ductal carcinoma in situ-G1).

CONCLUSIONS

In our external validation, the score showed a high negative predictive value and has the potential to reduce unnecessary surgeries or re-biopsies for ultrasound-detected B3-lesions by up to 39%.

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.

Three-year Trends in Diagnosis of B3 Breast Lesions and Their Upgrade Rates to Malignant Lesions

BACKGROUND

B3 breast lesions are a heterogeneous group with uncertain malignant potential and, as such, provide a source of diagnostic difficulty. We calculated the prevalence of B3 lesions at our center along with the upgrade rates (positive predictive value) to in situ or invasive malignancy.

MATERIALS AND METHODS

We searched our pathology database over a 3-year period to include all B3 biopsies. The subsequent excision for each biopsy was reviewed, and the rate of upgrade was calculated by subtype. These results were compared against data published in large United Kingdom studies.

RESULTS

A total of 9206 breast biopsies were identified, of which 614 (6.7%) were classified as B3. Lesions displaying epithelial atypia were the most common subtype of lesion, with a prevalence of 39.6%. Lesions displaying epithelial atypia were upgraded to malignancy in 35.7% of cases. Among non-atypical cases, papillary lesions were the most common diagnosis (32.1%) with an upgrade rate of 2%. In situ lobular neoplasia (10.4%) was the third most frequently encountered diagnosis, and was upgraded to malignancy in 10.9% of cases. The upgrade rate in the remaining non-atypical lesions was invariably low (0%-2.6%).

CONCLUSIONS

Herein, we have shown an overall B3 rate in keeping with published data, whereas lesions displaying epithelial atypia showed upgrade rates to malignancy comparable with that of large United Kingdom studies. In our study, lesions without epithelial atypia showed very low rates of upgrade. A wide range of upgrade rates is seen in cases of lobular neoplasia, which highlights the need for uniformity of nomenclature and reporting within this subtype to accurately ascertain the true risk of upgrade associated with these lesions.

Assessment and management of B3 breast lesions with atypia: a focused review

Breast lesions with atypia are a spectra of diseases that confer increased risk of breast cancer because of an increased probability of finding concomitant cancer after excision, or evolution toward in situ or invasive cancer over the long term. The widespread use of radiologic tools and core needle breast biopsies, in recent years, has led to an increase in the diagnosis of these atypical breast lesions. Concurrent with this has been an improvement in the classification and pathogenesis of these lesions. Current evidence suggests that the recognition and treatment of patients with atypical histology after biopsy and surgical excision requires a multidisciplinary approach to decrease the overdiagnosis and overtreatment risks. This focused review investigates the controversy and current management of atypical ductal hyperplasia, lobular neoplasia, flat epithelial atypia, and intraductal papilloma with atypia along with the risk-reducing strategies.

Outcome of radial scar/complex sclerosing lesion associated with epithelial proliferations with atypia diagnosed on breast core biopsy: results from a multicentric UK-based study

AIMS

The clinical significance of radial scar (RS)/complex sclerosing lesion (CSL) with high-risk lesions (epithelial atypia) diagnosed on needle core biopsy is not well defined. We aimed at assessing the upgrade rate to ductal carcinoma in situ (DCIS) and invasive carcinoma on the surgical excision specimen in a large cohort with RS/CSL associated with atypia.

METHODS

157 women with a needle core biopsy diagnosis of a RS/CSL with atypia and follow-up histology were studied. Histological findings, including different forms of the atypical lesions and final histological outcome in the excision specimens, were retrieved and analysed, and the upgrade rates for malignancy and for invasive carcinoma were calculated.

RESULTS

69.43% of the cases were associated with atypical ductal hyperplasia (ADH) or atypia not otherwise classifiable, whereas lobular neoplasia was seen in 21.66%. On final histology, 39 cases were malignant (overall upgrade rate of 24.84%); 12 were invasive and 27 had DCIS. The upgrade differed according to the type of atypia and was highest for ADH (35%). When associated with lobular neoplasia, the upgrade rate was 11.76%. The upgrade rate's variability was also considerably lower when considering the upgrade to invasive carcinoma alone for any associated lesion.

CONCLUSIONS

The upgrade rate for ADH diagnosed on needle core biopsy with RS is similar to that of ADH without RS and therefore should be managed similarly. RS associated with lobular neoplasia is less frequently associated with malignant outcome. Most lesions exhibiting some degree of atypia showed a similar upgrade rate to invasive carcinoma. Management of RS should be based on the concurrent atypical lesion.

Our Radiological Experience on B3 Lesions: Correlation Between Mammographic and MRI Findings With Histologic Definitive Result

INTRODUCTION

The purpose of this study was to evaluate mammographic and magnetic resonance imaging (MRI) features in B3 lesions.

PATIENTS AND METHODS

From 2011 to 2018, 139 patients with histologically proven B3 lesions who underwent mammography or/and MRI, were retrospectively reviewed. B3 lesions were classified in: atypical ductal hyperplasia (ADH), lobular neoplasia (LN), papillary lesion (PL), radial scar (RS), flat epithelial atypia (FEA), phyllodes tumor (PT), or mesenchymal lesion. Imaging features evaluated were: the presence of microcalcifications, mass and architectural distortions on mammograms and type of margins (circumscribed, irregular, spiculate), enhancement (mass-like, non-mass-like), size (≤ 15 mm, > 15 mm), and kinetics curves (I, II, III) on MRI. The definitive histologic results confirmed benign lesion or were upgraded to malignancy, and the positive predictive value was calculated.

RESULTS

Histologic classification of B3 lesions counted 45 (32.37%) ADH, 12 (8.63%) LN, 25 (17.99%) PL, 5 (3.61%) RS, 31 (22.31%) FEA, 20 (14.39%) PT, and 1 (0.70%) mesenchymal lesion. One hundred seven patients had mammography, and 38 had MRI. In 90 (65%) cases, the histologic diagnosis confirmed B3, in 15 (11%) cases, benign lesion, and in 34 (24%) cases, malignancies were found, with best positive predictive value for mesenchymal tumor (1), ADH (0.36), and FEA (0.4). Significant correlations comparing core needle biopsy groups and microcalcifications (P = .016) and presence of mass (P = .002) and comparing definitive histology with the presence of mass (P = .023), were found. Regarding MRI, the morphology correlated with core needle biopsy groups (P = .038); morphology (P = .024), dimension (P = .040), and kinetic curve (P = .005) correlated with malignancy.

CONCLUSIONS

The B3 category includes different entities, with various risk of malignancy; their heterogeneity is associated with specific mammographic and MRI features, although further confirmations are needed.

High risk (B3) breast lesions: What is the incidence of malignancy for individual lesion subtypes? A systematic review and meta-analysis

INTRODUCTION

Provide evidence to support evolving management strategies for high-risk (B3) breast lesions by assessing risk of carcinoma in subgroups of B3 lesions using systematic review and meta-analysis.

METHODS

Databases identified observational studies between 1980 and 2015 that reported on underestimation of malignancy following B3 lesion diagnosis at core needle biopsy. Critical appraisal, quality assessment, data extraction and meta-analysis was undertaken to calculate rate of malignancy of the whole B3 group and individual lesions. Study heterogeneity and association between variables and underestimation rate was investigated using random effects logistic modelling.

RESULTS

Meta-analysis, using data from 129 studies, assessed 11 423 lesions of which 2160 were upgraded to malignancy after surgical excision biopsy (17% malignancy rate, 95% CI 15-19%). Malignancy rates varied from 6% in radial scars with no atypia (95% CI 2-13%, I2 72.8%), to 32% in papillomas with atypia (95% CI 23-41%, I2 57.4%). Differences in upgrade rates between atypical and non-atypical lesions were statistically significant (p < 0.05). Study heterogeneity could not be explained by differences in core biopsy size or year of publication.

CONCLUSIONS

This comprehensive, inclusive assessment of all published literature, provides an accurate estimate of malignancy risk in subgroups of B3 lesions, to guide tailored management strategies. Some lesions have a high risk of malignancy, while others have a much lower risk, and could be safely managed with surveillance strategies rather than surgery.

A new risk stratification score for the management of ultrasound-detected B3 breast lesions

To develop a predictive scoring system for ultrasound-detected B3 lesions at ultrasound-guided core needle biopsy (US-CNB). A total of 2724 consecutive US-CNBs performed in our Institution (January 2011 to December 2014) were retrospectively reviewed. Inclusion criteria were as follows: (a) histopathological examination of the entire lesion or (b) availability of radiologic follow-up (FUP) ≥24 months. Patient- and lesion-related variables-patients' age, lesion consistency, lesion size, vascularization, BI-RADS category, and US-CNB result-were analyzed. Positive predictive values (PPVs) for malignancy were calculated correlating US-CNB results with excision histology or FUP. A scoring system for underlying malignancy was developed using risk factors weighting. A total of 102 B3 lesions were included: 27 atypical ductal hyperplasia (26.5%), 5 lobular intraepithelial neoplasia (4.9%), 32 radial scar (31.4%), 37 papillary lesions (36.3%), and 1 fibroepithelial lesion (0.9%). Surgery was performed on 71/102 (69.6%) lesions, and 22/71 were malignant; the remaining 31/102 lesions (30.4%) were unchanged at FUP. The overall PPV for malignancy was 21.6%. Patients' age (odds ratio [OR] = 3.63, P = 0.008), lesion consistency (OR = 5.96, P = 0.001), BI-RADS category (OR = 17.52, P < 0.001), and CNB result (OR = 3.6, P = 0.008) were associated with a higher risk of malignancy underestimation and selected as risk factors in the score definition. Two risk groups were identified: low (0-2 points) and high risk (3-5 points), with significantly different risk of malignancy underestimation (8.0% vs 59.3%, P < 0.001). The proposed score helps to predict the risk of malignancy underestimation and choose the management of B3 lesions at US-CNB.

Malignancy rates of B3-lesions in breast magnetic resonance imaging - do all lesions have to be excised?

BACKGROUND

Approximately 10% of all MRI-guided vacuum-assisted breast biopsies (MR-VAB) are histologically classified as B3 lesions. In most of these cases surgical excision is recommended. The aim of our study was to evaluate the malignancy rates of different B3 lesions which are visible on MRI to allow a lesion-adapted recommendation of further procedure.

METHODS

Retrospective analysis of 572 consecutive MR-VAB was performed. Inclusion criteria were a representative (=successful) MR-VAB, histologic diagnosis of a B3 lesion and either the existence of a definite histology after surgical excision or proof of stability or regression of the lesion on follow-up MRI. Malignancy rates were evaluated for different histologies of B3 lesions. Lesion size and lesion morphology (mass/non-mass enhancement) on MRI were correlated with malignancy.

RESULTS

Of all MR-VAB 43 lesions fulfilled the inclusion criteria. The malignancy rate of those B3 lesions was 23.3% (10/43). The highest malignancy rate was found in atypical ductal hyperplasia (ADH) lesions (50.0%; 4/8), 33.3% (2/6) in flat epithelial atypia (FEA), 28.6% (2/7) in lobular intraepithelial neoplasia (LIN) and 12.5% (2/16) in papillary lesions (PL). All 6 complex sclerosing lesions were benign. Mass findings were significantly more frequently malignant (31.3%, 10/32; p < 0.05) than non-mass findings (0/11). Small lesions measuring 5-10 mm were most often malignant (35.0%; 7/20). All large lesions (> 20 mm) were not malignant (0/10). Intermediate sized lesions (11-20 mm) turned out to be malignant in 23.1% (3/13).

CONCLUSIONS

The malignancy rate of B3 lesions which were diagnosed after MR-VAB was 23.3%. ADH, FEA and LIN showed considerable malignancy rates (50%, 33% and 29%) and should therefore undergo surgical excision. None of the cases, which were diagnosed as radial scars, non-mass enhancement or larger lesions (> 20 mm) were malignant. Here, a follow-up MRI seems to be advisable to avoid unnecessary operations.

TRIAL REGISTRATION

Retrospective study design, waived by the IRB.

Do clinical and radiologic features help predict malignancy of B3 breast lesions without epithelial atypia (B3a)?

OBJECTIVES

To evaluate excision histology outcome of B3a lesions diagnosed at imaging-guided core biopsy and assess whether clinical and radiologic features may predict upgrade to malignancy.

METHODS

A total of 153 B3a lesions (74 papillomas, 51 radial scars and 28 fibro-epithelial lesions) that underwent surgical excision were assessed. PPV for malignancy in all B3a lesions and specific for each sub-category was evaluated. Multivariate analysis was conducted to identify association between clinical (age, family or personal history of breast cancer, symptoms), diagnostic findings (imaging modality, lesion size, final BI-RADS category) and final excision outcome.

RESULTS

Eleven (7%) of 153 B3a lesions were upgraded to malignancy. All carcinomas diagnosed on excision were non-high grade DCIS. Following features were significantly associated with malignancy: lesions identified only on mammography (3/21; 14%), both mammography and ultrasound (7/44; 16%), lesion size > 10 mm (10/74; 13.5%) and BI-RADS category 4-5 (8/29; 27.6%). The absence of residual microcalcification after biopsy was associated with decreased risk for malignancy (15/16[93.7%]; p = 0.0297). Lesion size > 10 mm (OR = 9.3832; 95%; p = 0.0398) and BI-RADS category 4-5 (OR = 12.6004; 95%; p = 0.0006) were found to be independent predictors of upgrade to malignancy.

CONCLUSIONS

B3a lesions are associated with low risk of malignancy at excision. Lesion size > 10 mm and BI-RADS 4-5 category may represent useful predictors of upgrade to malignancy.

The B3 conundrum-the radiologists' perspective

The management of B3 lesions is both controversial and complicated. There have been recent publications regarding how best to manage this heterogeneous group particularly in light of the Marmot Review and with the advent of vacuum-assisted biopsy technique. It is recognized that B3 lesions on core biopsy can be upgraded to malignancy in up to one-third of cases, but this is predominantly to ductal carcinoma in situ or low-grade invasive tumours. The upgrade rate is mainly associated with B3 lesions with epithelial atypia. This review summarizes the current management and focuses on the proposed future management of these B3 lesions.

B3-lesions of the breast and cancer risk - an analysis of mammography screening patients

The use of mammography screening, followed by needle core biopsy (NCB), is associated with an increasing amount of invasive procedures. A considerable amount of specimens must be classified as lesions with uncertain malignant potential (B3-lesion). In these cases, an open biopsy is indicated for further diagnosis. We evaluated patients with B3-lesions to determine the risk of malignancy corresponding to the histopathological NCB results and the type of radiological lesion identified. A total of 95 patients participating in the German mammography screening program with a B3-lesion following NCB (104 B3-lesions in total) were included in our analysis. We analyzed the correlation between the initial histopathological findings from the NCB specimen and cancer risk. We further analyzed the correlations of malignant results with the type of mammographic lesion. In 23 cases (22%), histopathological examination following excision revealed a malignant lesion, including invasive and in situ carcinoma. The positive predictive value of the subgroups of B3-lesions ranged between 0.11 and 0.31; the B3-lesion associated with the highest cancer risk was the atypical ductal hyperplasia; however, no significant difference was observed between the B3-lesion subgroups (P=0.309) regarding the risk of malignancy. Comparing the different types of mammographic findings, such as radiological mass or microcalcifications, there was no significant difference in the risk for malignancy (P=0.379). The different types of B3-lesions did not exhibit differences in the risk for malignancy, and the morphological type of mammographic lesion does not appear to be correlated with cancer risk; therefore, our results underline the need for open biopsy in patients with B3-lesions following NCB.

Role of Breast Imaging in Predicting Outcome of Lesions of Uncertain Malignant Potential (B3) Diagnosed at Core Needle Biopsy

Aims

To elucidate whether breast imaging can predict final histologic diagnosis of lesions of uncertain malignant potential diagnosed at ultrasound core needle biopsy (CNB).

Methods

The imaging characteristics (mammography, ultrasound, and magnetic resonance imaging [MRI]) of lesions of uncertain malignant potential in the breast that were obtained by ultrasound CNB were retrospectively analyzed in 87 women. Radiologic characteristics of lesions were compared to definitive histopathologic findings.

Results

Out of 87 breast lesions of uncertain malignant potential, 27 (31%) were diagnosed as papillary lesions, 24 (28%) atypical ductal hyperplasia, 19 (22%) lobular intraepithelial neoplasia, 9 (10%) phyllodes tumors, 3 (3%) radial sclerosing lesions, and 5 (6%) unspecified lesions of uncertain malignant potential. The underestimation rate of malignancy at CNB based on the total number of lesions on final follow-up was 22%. Using multivariate logistic regression, Breast Imaging-Reporting and Data System (BI-RADS) score (odds ratio [OR] = 12.29, p = 0.027) and Göttingen MRI scoring system (OR = 8.1, p = 0.008) were found to be independent predictors of malignancy. Receiver operating characteristic analysis showed that Göttingen MRI score >3 provides a plausibly good cutoff value with sensitivity of 100 (95% confidence interval [CI] 74%-100%) and specificity of 76% (95% CI 61%-88%).

Conclusions

Lesions of uncertain malignant potential classified as BI-RADS 5 and Göttingen score 4 or higher are at significantly higher risk of harboring malignancy and therefore should be recommended for surgical excision.