Upgrade risk of image-targeted radial scar and complex sclerosing lesions diagnosed at needle-guided biopsy: a retrospective study

OBJECTIVES

To determine the upgrade rate of radial scar (RS) and complex sclerosing lesions (CSL) diagnosed with percutaneous biopsy. The secondary objectives were to determine the new atypia rate after surgery and to assess the diagnosis of subsequent malignancy on follow-up.

METHODS

This single-institution retrospective study had IRB approval. All image-targeted RS and CSL diagnosed with percutaneous biopsy between 2007 and 2020 were reviewed. Patient demographics, imaging presentation, biopsy characteristics, histological report, and follow-up data were collected.

RESULTS

During the study period, 120 RS/CSL were diagnosed in 106 women (median age, 43.5 years; range, 23-74), and 101 lesions were analyzed. At biopsy, 91 (90.1%) lesions were not associated with another atypia or malignancy and 10 (9.9%) were associated with another atypia. Out of the 91 lesions that were not associated with malignancy or atypia, 75 (82.4%) underwent surgical excision, and one upgrade to low-grade CDIS was detected (1.3%). Among the 10 lesions initially associated with another atypia, 9 were surgically excised and no malignancy was detected. After a median follow-up of 47 months (range: 12-143 months), two (1.98%) developed malignancy in a different quadrant; in both cases, another atypia was present at biopsy.

CONCLUSION

We found a low upgrade rate on image-detected RS/CSL, with or without another atypia associated. Associated atypia was underdiagnosed at biopsy in almost one-third of cases. Subsequent cancer risk could not be established because the only two cases were associated with another high-risk lesion (HRL), which might have increased the patient's risk of developing malignancy.

CLINICAL RELEVANCE STATEMENT

Our upgrade rates of RS/CSL with or without atypia diagnosed with core needle biopsy are almost as low as the ones reported with larger sampling methods. This result has particular importance in places with limited accessibility to US-guided vacuum-assisted biopsy.

KEY POINTS

•New evidence is showing lower upgrade rates of RS and CSL after surgery, leading to a more conservative management with extensive sampling using VAB or VAE. •Our study showed only one upgrade to a low-grade DCIS after surgery, yielding an upgrade rate of 1.33%. •During follow-up, no new malignancy was detected in the same quadrant where RS/CSL was diagnosed, including patients without surgery.

Imaging and Management of Radial Scars and Complex Sclerosing Lesions

Radial scars and complex sclerosing lesions, often collectively referred to as radial sclerosing lesions (RSLs), are breast lesions characterized by sclerotic stroma with entrapped epithelial elements. RSLs have imaging features that overlap with those of breast malignancy and often become the target of imaging-guided biopsy given their suspicious imaging appearance. These can be identified in isolation or can also be associated with atypia or other high-risk lesions that have intrinsic malignant potential, increasing the risk of carcinoma and affecting prognosis and management of RSLs. Because of this, management of these lesions remains controversial. Traditional management has been surgical excisional biopsy. However, as more RSLs are identified (because digital breast tomosynthesis allows identification of more architectural distortions), optimal management is evolving. Physicians in some practices are using a multidisciplinary approach to the management of RSLs when deciding on surgical excision of these lesions versus imaging follow-up. These discussions also incorporate individual patient risk factors and greater patient informed medical decision making. Reported upgrade rates of RSLs at core needle biopsy vary and can depend on the sampling method, number of samples, gauge of the needle, target being sampled, and radiologic-pathologic concordance or discordance. A precise sampling technique also allows greater accuracy of diagnosis and lower upgrade rates for these lesions, with radiologic-pathologic correlation as an integral component for further management decisions. The authors review the overall histopathologic, clinical, and imaging features of RSLs and discuss appropriate management based on currently available data regarding upgrade rates. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

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 Scars and Complex Sclerosing Lesions of the Breast: Prevalence of Malignancy and Natural History Under Active Surveillance

BACKGROUND

When needle core biopsies (NCBs) of the breast reveal radial scar or complex sclerosing lesions (RSLs), excision is often recommended despite a low risk of malignancy in the modern era. The optimal management of NCBs revealing RSLs is controversial, and understanding of the natural history of unresected RSLs is limited.

METHODS

We retrospectively analyzed pathology and imaging data from 148 patients with NCB revealing RSL without atypia from 2015 to 2019 to determine the prevalence of malignancy and the behavior of RSLs undergoing active surveillance (AS).

RESULTS

The mean age of patients was 52 years, and most lesions were screen-detected (91%). The median lesion size was 6.0 mm (range 2-39). Most patients (66%, n = 98) underwent immediate surgery, while 34% (n = 50) of patients underwent AS, with a median follow-up of 16 months (range 6-51). Of the excised RSLs, 99% (n = 97) were benign and 1% (n = 1) revealed ductal carcinoma in situ (DCIS). In 17% (n = 17) of cases, additional high-risk lesions were discovered upon excision. Among the 50 patients undergoing AS, no lesions progressed on interval imaging.

CONCLUSIONS

In this cohort, 99% of RSLs undergoing excision were benign, 1% revealed DCIS, and there were no invasive cancers. In the first study of patients with RSLs undergoing AS, we found that all lesions either remained stable or resolved. We propose that the vast majority of patients with RSL on NCB can be safely offered AS, and that routine excision is a low-value intervention.

Radial scars and complex sclerosing lesions on core needle biopsy of the breast: upgrade rates and long-term outcomes

PURPOSE

Radial scars and complex sclerosing lesions of the breast are part of a group of "indeterminate" breast lesions, which are excised due to risk of coexistent carcinoma. The aim of this study was to assess rate of upgrade of these lesions to invasive and in situ carcinoma and to quantify the risk of development of subsequent cancer in women diagnosed with these lesions.

METHODS

A retrospective review of a prospectively maintained breast screening database was performed. All patients with radial scar identified at either core biopsy or final excision biopsy between January 2006 and July 2012 were identified. Full pathological reports for both core biopsy and final excision biopsy were reviewed. Patient outcomes were followed for a mean of 117.1 months.

RESULTS

Of 451 B3 biopsies performed at our screening unit, 95 (22%) were found to have a radial scar or complex sclerosing lesion (CSL) on core needle biopsy. Within this group, 77 had no atypia on CNB, with 7 (9%) upgraded to invasive/in situ carcinoma on final excision. Of nine with definite atypia on CNB, 3 (33%) were upgraded. In those patients without atypia or malignancy on final excision, 7.5% developed cancer during 10-year follow-up.

CONCLUSION

Patients with radial scar with atypia have a higher risk of upgrade to malignancy. Further research is needed to identify which patients may safely avoid excision of radial scar. Patients with a diagnosis of radial scar on CNB are at increased subsequent risk of breast cancer and may benefit from additional screening.

Is radial scar on core needle biopsy a risk factor for malignancy? A single-center retrospective review and implications for management

INTRODUCTION

Reported upgrade rate to malignancy of radial scars (RS) ranges widely (0%-40%) making management controversial.

METHODS

A retrospective chart review was performed on patients with RS on core needle biopsy (CNB). Upgrade rates to malignancy and atypia on surgical excision were evaluated.

RESULTS

Of 127 patients with RS on CNB, 53 were excluded due to malignancy or missing records. Of 74 patients reviewed, 52 (70.3%) had surgical excision with four (7.7%) upgraded to malignancy. Eight patients (10.8%) had atypia with RS on CNB with two (25%) upgraded to malignancy. When isolated RS was on CNB, 2 of 44 (4.5%) upgraded to malignancy while 15 of 44 (34%) had atypia on excision. Of 22 patients (29.7%) who did not have excision, zero developed cancer.

CONCLUSION

We found higher than expected upgrade rates of isolated RS to atypia which can alter management. Additionally, 25% of RS with atypia upgraded to malignancy suggesting these patients are at higher risk.

Digital Mammography Stereotactic Biopsy versus Digital Breast Tomosynthesis-guided Biopsy: Differences in Biopsy Targets, Pathologic Results, and Discordance Rates

Background Digital breast tomosynthesis (DBT)-guided biopsy is increasingly used in practice. It is important to know expected changes in biopsy targets, pathologic results, and discordance rates. Purpose To compare biopsy target types, pathologic results, and discordance rates for 2 years preceding and 2 years following implementation of DBT-guided biopsy. Materials and Methods All 9-gauge vacuum-assisted core biopsies from a single tertiary breast center that used digital mammography (DM) stereotactic guidance from 2013 to 2015 and DBT-guided biopsy from 2015 to 2017 were retrospectively reviewed. All mammographic examinations were performed with DBT. Patient demographics, biopsy target type, pathologic reports, surgical excision specimens when available, breast density, and imaging follow-up results were recorded. Biopsy targets and discordance rates between radiologic and pathologic examinations were compared between the two biopsy groups. Generalized mixed modeling was used to examine results before and after DBT-guided biopsy. Results A total of 1313 women underwent 1405 breast biopsies: 643 by using DM (August 2013 to July 2015) (median age, 56 years; interquartile range, 49-66 years) and 762 by using DBT (August 2015 to July 2017) (median age, 58 years; interquartile range, 50-67 years), (P = .58). Calcifications were the most common biopsy target for both groups, constituting 89.9% (578 of 643) of DM-guided biopsies and 71.1% (542 of 762) of DBT-guided biopsies (P = .03). The rate of architectural distortion biopsies was 2.0% (13 of 643) with DM-guided biopsy and 17.7% (135 of 762) with DBT-guided biopsy (P = .01). Although overall malignancy rate was similar for DM-guided biopsy (27.8% [179 of 643]) and DBT-guided biopsy (24.8% [191 of 762], P = .54), DBT-guided biopsy helped identify a similar percentage of invasive malignancies (37.4% [72 of 191] vs 29.0% [52 of 179] at DM P = .35), but more radial sclerosing lesions (8.3% [95% confidence interval {CI}: 6.0, 10.0] vs 1.7% [95% CI: 1.0, 3.1]) (P = .01). The discordance rate was 1.4% (95% CI: 1.0, 2.7) with DM-guided biopsy and 4.5% (95% CI: 3.2, 6.3) with DBT-guided biopsy (P = .01). Of the 34 discordant DBT-guided biopsies, 30 were architectural distortions. Conclusion With the transition to digital breast tomosynthesis-guided biopsy, more architectural distortions were biopsied, more radial sclerosing lesions were identified, and more discordance existed in radiologic and pathologic examinations, with a similar percentage of carcinomas diagnosed. © RSNA, 2020 Online supplemental material is available for this article.

Reducing indications for radial scar surgical excision in Slovenian breast cancer screening program

PURPOSE

Management of the radial scar (RS)/complex sclerosing lesion (CSL) diagnosed by core needle biopsy (CNB) in breast cancer screening population (BCSP) is controversial due to its intrinsic malignant potential. We aimed to determine (i) the rate of upgrade of the RS/CSL to malignant lesions and (ii) radiological characteristics and CNB histopathological findings of the lesions related to the upgrade of the RS/CSL to malignant lesions after surgical excision in our BCSP.

PATIENTS AND METHODS

Database of Slovenian National Breast Cancer Screening Program was checked for terms RS/CSL in all patients who underwent CNB in the period 2008-2018. The ratios of upgrade from CNB RS/SCL to malignant lesions after surgical excision were calculated with specific interest to the radiological characteristics and the CNB patohistologically findings of the lesions.

RESULTS

Of 162 patients with diagnosis of RS/CSL on the CNB, 121/156 (78%) cases underwent surgical excision. 6 of 121 (5%) cases were upgraded to a malignant diagnosis in surgical specimen, 3 cases of invasive carcinoma and 3 cases of DCIS, respectively. Five of the upgraded cases (5/6, 83.3%) showed atypical epithelial proliferative lesions (AEPL) on CNB. In one upgraded case without AEPL the lesion presented as 33 mm architectural distortion with microcalcifications on the mammogram.

CONCLUSIONS

In BCSP setting RS/CSL without AEPL/papilloma and those measuring less than 2 cm in the largest diameter can be followed radiologically. Increasing the number of cores and adequate sampling of the periphery and the centre of the RS/CSL improves the pick-up rate of associated atypia/malignancy.

Second International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions)

Purpose

The second International Consensus Conference on B3 lesions was held in Zurich, Switzerland, in March 2018, organized by the International Breast Ultrasound School to re-evaluate the consensus recommendations.

Methods

This study (1) evaluated how management recommendations of the first Zurich Consensus Conference of 2016 on B3 lesions had influenced daily practice and (2) reviewed current literature towards recommendations to biopsy.

Results

In 2018, the consensus recommendations for management of B3 lesions remained almost unchanged: For flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL) and radial scars (RS) diagnosed on core-needle biopsy (CNB) or vacuum-assisted biopsy (VAB), excision by VAB in preference to open surgery, and for atypical ductal hyperplasia (ADH) and phyllodes tumors (PT) diagnosed at VAB or CNB, first-line open surgical excision (OE) with follow-up surveillance imaging for 5 years. Analyzing the Database of the Swiss Minimally Invasive Breast Biopsies (MIBB) with more than 30,000 procedures recorded, there was a significant increase in recommending more frequent surveillance of LN [65% in 2018 vs. 51% in 2016 (p = 0.004)], FEA (72% in 2018 vs. 62% in 2016 (p = 0.005)), and PL [(76% in 2018 vs. 70% in 2016 (p = 0.04)] diagnosed on VAB. A trend to more frequent surveillance was also noted also for RS [77% in 2018 vs. 67% in 2016 (p = 0.07)].

Conclusions

Minimally invasive management of B3 lesions (except ADH and PT) with VAB continues to be appropriate as an alternative to first-line OE in most cases, but with more frequent surveillance, especially for LN.

Radial scar on image-guided breast biopsy: is surgical excision necessary?

PURPOSE

Radial scar's stellate appearance may mimic carcinoma mammographically and histologically. Management of radial scar (RS) found on breast core needle biopsies (CNB) ranges from excision to clinical observation due to the variation in reported upgrades to malignancy at surgical excision. We examined the upgrade rate in patients with RS detected on CNB at our institution and reviewed the current literature.

METHODS

A retrospective study was conducted of all cases with RS diagnosed on CNB between December 2006 and March 2017 at our institution. Inclusion criteria were patients with "pure" RS and RS associated with high-risk lesions (HRL). Upgrade was defined as invasive or non-invasive cancer in the excisional biopsy.

RESULTS

157 cases were identified with RS on CNB, and 122 cases met inclusion criteria. Of these 122 cases, 91 (75%) had pure RS on CNB while 31 (25%) had associated atypia or HRL. 81 (66%) of patients proceeded to excisional biopsy and 41 (34%) did not. Two patients (1.6% of total) were found to have a low-grade invasive ductal carcinoma (0.6 and 0.8 cm) upon surgical excision. None of the remaining 120 patients developed an ipsilateral breast cancer with a mean of 32.3-month follow-up.

CONCLUSIONS

We found a very low upgrade rate to breast cancer when RS was found on CNB with or without associated HRL. Our results are consistent with other reported series. Our data do not support surgical excision for RS but rather close clinical follow-up for patients with RS on CNB.

Radial Scars of the Breast Encountered at Core Biopsy: Review of Histologic, Imaging, and Management Considerations

OBJECTIVE

The purposes of this article are to place the controversy over the management of radial scars diagnosed at core biopsy in perspective and to define reasonable management options.

CONCLUSION

The management of radial scars after image-guided core biopsy of the breast for diagnosis remains controversial. Although current literature suggests no premalignant potential of these lesions, it does not fully explain the small but real percentage of these lesions that are upgraded to malignancy after surgical excision. This upgrade phenomenon is probably best explained by core biopsy sampling error. A recommendation minimizing this possibility based on lesion size seems reasonable.