Management of radial scars/complex sclerosing lesions of the breast diagnosed on vacuum-assisted large-core biopsy: is surgery always necessary?

Adenosquamous proliferation in radial sclerosing lesions: Histologic spectrum and key features in systematic review of 247 lesions

Adenosquamous proliferation (ASP) is known to occur in the central nidus of radial sclerosing lesions (RSL) of the breast. However, their significance is debated and remains largely unknown. In addition, there is a histologic overlap between ASP and low-grade adenosquamous carcinomas (LGASC). We conducted a large retrospective review of 247 RSLs to evaluate the prevalence of ASP and quantitatively analyze associated histologic features of RSLs including size, stromal cellularity, and presence of chronic inflammation. The central nidus of RSLs were classified as hyalinized in 121 cases (49%), cellular in 37 cases (15%), and equally mixed hyalinized and cellular in 89 (36%). ASP occurred in 92 of 247 RSLs (37.2%). Cases with ASP were significantly associated with a cellular stroma; 78.4% of RSLS with cellular stroma had ASP versus just 11.6% of hyalinized RSLs. In our large cohort, inflammation is commonly found in RSLs with ASP (p= <0.001). In conclusion, we confirm that ASP is statistically more likely to be found in RSLs with a cellular stroma. In addition, ASP is commonly associated with chronic inflammation. The finding challenges the notion that prominent lymphocytes are a diagnostic clue to LGASC on limited biopsy material.

Breast MRI: an illustration of benign findings

Despite its unparalleled sensitivity for aggressive breast cancer, breast MRI continually excites criticism for a specificity that lags behind that of modern mammographic techniques. Radiologists reporting breast MRI need to recognise the range of benign appearances on breast MRI to avoid unnecessary biopsy. This review summarises the reported diagnostic accuracy of breast MRI with particular attention to the technique's specificity, provides a referenced reporting strategy and discusses factors that compromise diagnostic confidence. We then present a pictorial review of benign findings on breast MRI. Enhancing radiological skills to discriminate malignant from benign findings will minimise false positive biopsies, enabling optimal use of multiparametric breast MRI for the benefit of screening clients and breast cancer patients.

Radiomics Based on DCE-MRI Improved Diagnostic Performance Compared to BI-RADS Analysis in Identifying Sclerosing Adenosis of the Breast

Purpose

Sclerosing adenosis (SA) is a benign lesion that could mimic breast carcinoma and be evaluated as malignancy by Breast Imaging-Reporting and Data System (BI-RADS) analysis. We aimed to construct and validate the performance of radiomic model based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) compared to BI-RADS analysis to identify SA.

Methods

Sixty-seven patients with invasive ductal carcinoma (IDC) and 58 patients with SA were included in this retrospective study from two institutions. The 125 patients were divided into a training cohort (n= 88) from institution I and a validation cohort from institution II (n=37). Dynamic contrast-enhanced sequences including one pre-contrast and five dynamic post-contrast series were obtained for all cases with different 3T scanners. Single-phase enhancement, multi-phase enhancement, and dynamic radiomic features were extracted from DCE-MRI. The least absolute shrinkage and selection operator (LASSO) logistic regression and cross-validation was performed to build the radscore of each single-phase enhancement and the final model combined multi-phase and dynamic radiomic features. The diagnostic performance of radiomics was evaluated by receiver operating characteristic (ROC) analysis and compared to the performance of BI-RADS analysis. The classification performance was tested using external validation.

Results

In the training cohort, the AUCs of BI-RADS analysis were 0.71 (95%CI [0.60, 0.80]), 0.78 (95%CI [0.67, 0.86]), and 0.80 (95%CI [0.70, 0.88]), respectively. In single-phase analysis, the second enhanced phase radiomic signature achieved the highest AUC of 0.88 (95%CI [0.79, 0.94]) in distinguishing SA from IDC. Nine multi-phase radiomic features and two dynamic radiomic features showed the best predictive ability for final model building. The final model improved the AUC to 0.92 (95%CI [0.84, 0.97]), and showed statistically significant differences with BI-RADS analysis (p<0.05 for all). In the validation cohort, the AUC of the final model was 0.90 (95%CI [0.75, 0.97]), which was higher than all BI-RADS analyses and showed statistically significant differences with one of the BI-RADS analysis observers (p = 0.03).

Conclusions

Radiomics based on DCE-MRI could show better diagnostic performance compared to BI-RADS analysis in differentiating SA from IDC, which may contribute to clinical diagnosis and treatment.

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

INTRODUCTION

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

METHODS

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

OUTCOMES

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

RESULTS

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

CONCLUSION

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

Underestimation Rate in the Percutaneous Diagnosis of Radial Scar/Complex Sclerosing Lesion of the Breast: Systematic Review

OBJECTIVE

 To evaluate the underestimation rate in breast surgical biopsy after the diagnosis of radial scar/complex sclerosing lesion through percutaneous biopsy.

DATA SOURCES

 A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. The PubM: ed, SciELO, Cochrane, and Embase databases were consulted, with searches conducted through November 2020, using specific keywords (radial scar OR: complex sclerosing lesion, breast cancer, anatomopathological percutaneous biopsy AND/OR: surgical biopsy).

DATA COLLECTION

 Study selection was conducted by two researchers experienced in preparing systematic reviews. The eight selected articles were fully read, and a comparative analysis was performed.

STUDY SELECTION

 A total of 584 studies was extracted, 8 of which were selected. One of them included women who had undergone a percutaneous biopsy with a histological diagnosis of radial scar/complex sclerosing lesion and subsequently underwent surgical excision; the results were used to assess the underestimation rate of atypical and malignant lesions.

DATA SYNTHESIS

 The overall underestimation rate in the 8 studies ranged from 1.3 to 40% and the invasive lesion underestimation rate varied from 0 to 10.5%.

CONCLUSION

 The histopathological diagnosis of a radial scar/complex sclerosing lesion on the breast is not definitive, and it may underestimate atypical and malignant lesions, which require a different treatment, making surgical excision an important step in diagnostic evaluation.

Malignancy Upgrade Rates of Radial Sclerosing Lesions at Breast Cancer Screening

Purpose To determine the upgrade rate for biopsy-proven radial scars and radial sclerosing lesions (RS). Materials and Methods In this retrospective study, radiology and pathology databases from two tertiary breast centers were searched to identify patients with biopsy-confirmed RS between March 1, 2012, and December 31, 2017, during which all mammography was performed with digital breast tomosynthesis (DBT). Adjunct modalities such as MRI or US are performed at our centers to better characterize lesions identified at DBT. Patient demographics, imaging, needle and excisional biopsies, and follow-up data were collected at the patient level. Clopper-Pearson interval estimate for upgrade was calculated for 95% confidence using PropCIs package with R version 4.1.0 (R Foundation for Statistical Computing) (1). Results During the study period, a total of 155 885 DBT examinations were performed. From these examinations, 146 biopsy-proven RS were identified in 142 women (median age, 58 years; age range, 26-87 years). A total of 80.1% (117 of 146) of all RS did not have associated atypia or malignancy, and 19.9% (29 of 146) had associated atypia at initial biopsy. A total of 66.7% (78 of 117) of RS without atypia or malignancy were surgically excised, 25.6% (30 of 117) were followed (median, 3 years; range, 1-7 years) with benign findings on imaging, and 7.7% (nine of 117) were lost to follow-up. The rate of malignancy upgrade was 0.9% (one of 117 [95% CI: 0.02, 4.7]); one RS without concurrent atypia or malignancy demonstrated invasive carcinoma at surgical excision. Conclusion RS without atypia had a low upgrade rate. Keywords: Mammography, Breast © RSNA, 2021.

Pure Radial Scars Do Not Require Surgical Excision When Concordant and Benign at Image-guided Breast Biopsy

OBJECTIVE

To determine the best management option (surgical excision versus imaging surveillance) following the diagnosis of pure radial scars (RSs) and RSs with associated additional high-risk lesions (HRLs) encountered on percutaneous core-needle breast biopsy.

METHODS

An IRB-approved retrospective review of the breast imaging reporting system database was performed to identify all cases of pure RS alone or RS plus an additional HRL (papilloma, atypia, lobular neoplasia) diagnosed on core-needle biopsy, from 2007 to 2016, at four breast centers in our institution. Cases with associated malignancy, discordant radiologic-pathologic results, or those lost to follow-up were excluded. The remaining cases were evaluated to determine results of either subsequent surgical excision or long-term follow-up imaging (minimum of two years). Additional data recorded included clinical presentation, breast density, personal and family history of breast cancer, lesion imaging characteristics, and biopsy method.

RESULTS

The study cohort included 111 patients with 111 lesions: 56.8% (63/111) with RS alone (pure) and 43.2% (48/111) with RS plus additional HRL(s). Out of the 63 radiologic-pathologic concordant pure RSs, there were no upgrades to malignancy in 51 subsequent surgical excisions or 12 long-term surveillance cases (0/63, 0%). Out of the 48 RSs plus additional HRL(s), there were 2 upgrades to malignancy (2/48, 4.2%).

CONCLUSION

Cases of radiologic-pathologic concordant pure RS diagnosed at core-needle biopsy do not require surgical excision. On the other hand, surgical excision should be considered for RS plus additional HRLs diagnosed at core-needle biopsy.

Radial Scar: a management dilemma

Radial scar (RS) or complex sclerosing lesions (CSL) if > 10 mm is a benign lesion with an increasing incidence of diagnosis (ranging from 0.6 to 3.7%) and represents a challenge both for radiologists and for pathologists. The digital mammography and digital breast tomosynthesis appearances of RS are well documented, according to the literature. On ultrasound, variable aspects can be detected. Magnetic resonance imaging contribution to differential diagnosis with carcinoma is growing. As for the management, a vacuum-assisted biopsy (VAB) with large core is recommended after a percutaneous diagnosis of RS due to potential sampling error. According to the recent International Consensus Conference, a RS/CSL lesion, which is visible on imaging, should undergo therapeutic excision with VAB. Thereafter, surveillance is justified. The aim of this review is to provide a practical guide for the recognition of RS on imaging, illustrating radiological findings according to the most recent literature, and to delineate the management strategies that follow.

Significance of adenosquamous proliferation in breast lesions

Adenosquamous proliferation (ASP), characterised by ductal structures with a dual glandular and squamous phenotype within desmoplastic stroma, is essentially a hallmark of various sclerosing lesions of the breast (SL) and breast lesions with sclerosis (BLWS), not including sclerosing adenosis. In radial scar/complex sclerosing lesion (RS/CSL), clonality has been previously demonstrated in microdissected ASP. SL/BLWS encompass a diverse range of pathological entities that historically have an equally diverse list of names, often for histologically alike or identical lesions at different anatomical locations. In common they are comprised of one or more components of fibrocystic or proliferative breast disease and papillomata, which become distorted and even obliterated by a sclerosing process that appears to be associated with and/or secondary to ASP, which in an individual lesion may be inconspicuous at the time of biopsy. The histological overlap of various SL/BLWS with RS/CSL, in which a nidus containing ASP is pathognomonic of early lesions, also supports a common element of ASP across various SL/BLWS. SL/BLWS show an interesting association with low-grade metaplastic carcinoma, particularly low-grade adenosquamous carcinoma (LGASC) with which, they appear to form a histological and possible biological spectrum because ASP and LGASC share similar histological and immunophenotypical characteristics. The presentation of ASP in various SL/BLWS will be discussed.

Magnetic Resonance Imaging Assessment of Radial scars/complex Sclerosing Lesions of the Breast

PURPOSE

To describe the magnetic resonance characteristics of radial scars/complex sclerosing lesions (RS/CSL) of the breast using the current BI-RADS lexicon. To investigate the value of diffusion weighted imaging to predict malignancy.

PATIENTS AND METHODS

From 2010 to 2017 we have found 25 women with architectural distortion at mammography who underwent surgical resection with a final hystopathologic report of RS/CSL. For description of MRI findings we adhered to BI-RADS classification (5th edition).

RESULTS

The final pathological diagnosis was: "pure" RS/CSL in 7 cases (28%), RS/CSL with associated high risk lesions in 12 (48%) and 6 cases (24%) were associated with malignancy. Magnetic resonance findings: four of 25 negative or focus. Five of 25 mass enhancement: irregular, non circumscribed spiculated mass with heterogeneous or rim enhancement and most with type II curves. Sixteen of 25 non mass enhancement: focal or linear distribution and heterogeneous internal enhancement most with type I curves. Six of 25 had cancer associated with the complex sclerosing lesion. All six showed non-mass, focal and clustering-ring enhancement. Two cases with invasive breast carcinoma had ADC values under 1.15 x10-3 mm/s while most of the rest had values above.

CONCLUSION

Most RS/CSL showed enhancement at MR. The predominant pattern was a non-mass, focal, heterogeneous internal enhancement with type 1 curves. All cases with associated cancer showed non mass enhancement. Invasive breast cancers had ADC values < 1.15 10-3 s/mm2.