Radial scar lesions of the breast diagnosed by needle core biopsy: analysis of cases containing occult malignancy

Nonneoplastic and neoplastic sclerosing lesions of the breast

Sclerosing lesions of the breast encompass a spectrum of benign and malignant entities and often pose a diagnostic challenge. Awareness of key morphologic features and pitfalls in the assessment of morphology and immunophenotype is essential to avoid over- or underdiagnosis and ensure optimal clinical management. This review summarizes nonneoplastic sclerosing lesions such as radial scar/complex sclerosing lesion, sclerosing adenosis, sclerosing intraductal papilloma, sclerosing variants of ductal adenoma and nipple adenoma, and fibroadenoma with extensive sclerosis, including their clinical presentation, characteristic morphology, differential diagnostic considerations, appropriate immunohistochemical work-up, when needed, and the clinical significance. In addition, atypical or neoplastic entities (such as atypical ductal hyperplasia, ductal carcinoma in situ, low-grade adenosquamous carcinoma, and fibromatosis-like metaplastic carcinoma) that can involve these sclerosing lesions are also briefly discussed.

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.

Upstage Rate of Complex Sclerosing Lesions/Radial Scars

BACKGROUND

Radial scars (RS) and complex sclerosing lesions (CSL) are breast radiologic findings described as small, stellate lesions causing architectural distortion. This can mimic malignancy. Core needle biopsy (CNB) is often performed. Advances in breast imaging have led to increased detection of RS/CSL. The upstage rate of RS/CSL to in situ or invasive disease is 0-40%. We sought to determine the upstaging rate of RS/CSL to in situ, invasive disease, or high-risk lesion at our institution to create excision guidelines.

METHODS

The pathology database of a single center was searched for RS/CSL, from January 2013 to September 2020. We included CNB without malignancy or high-risk lesion (eg, atypical ductal hyperplasia). Patient demographics, indications for biopsy, imaging findings, biopsy procedure, and final pathology were collected.

RESULTS

Forty-four patients were included. 52.3% had CNB for architectural distortion on mammography, 18.2% for mass, 11.4% for calcifications, 2.3% for abnormal MRI, and 15.9% for multiple reasons (eg, calcifications and mass). Most had an ultrasound: 43.2% had no abnormality and 34.1% had a mass. All CNB were vacuum assisted, 65.9% with 9-gauge needle, and averaged 10.0 cores. 77.3% were stereotactic biopsies, 13.6% ultrasound, and 6.8% MRI. 59.1% had excision after CNB. 82.1% of patients did not upstage. One patient upstaged to invasive ductal carcinoma (3.6%) and two patients to high-risk lesion (7.1%).

DISCUSSION

There was low upstage rate of RS/CSL on excisional biopsy. Centers could consider close surveillance for RS/CSL on CNB. Longer follow-up in cases of deferred excision is needed to ensure oncologic safety.

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.

Imaging Follow-up Versus Surgical Excision for Radial Scars Identified on Tomosynthesis-Guided Core Needle Biopsy

RATIONALE AND OBJECTIVES

We investigated if imaging or pathology features could determine when imaging follow-up is appropriate after diagnosis of radial scar on digital breast tomosynthesis (DBT)-guided core needle biopsy (CNB).

MATERIALS AND METHODS

We conducted a retrospective review of all patients diagnosed with radial scars on DBT-guided CNB at our institution between November 2014 and December 2016. Cases were excluded if DCIS or invasive malignancy was present in the same core specimens. Patient age; needle size; number of cores; visibility on full-field digital mammography versus DBT; lesion size; presence of architectural distortion, mass, or calcifications; imaging stability; presence or absence of atypia; length of imaging follow-up, and excisional pathology were collected.

RESULTS

Of 45 eligible biopsies, 6 cases had radial scars with associated atypia and 39 cases had no associated atypia. Twenty-four patients underwent surgical excision, including all patients with atypia on CNB. One case (4%) was upstaged to DCIS on surgical excision after CNB revealed a radial scar with associated ADH. There was also a case without atypia on CNB, but excisional pathology revealed associated ADH. In cases with radial scars and associated atypia on CNB, the upstage rate was 17%. In cases without atypia on CNB that underwent surgical excision, the upstage rate was 0%. Imaging follow-up was available in 13 patients who did not undergo surgical excision, with stability in all 13 with a median follow-up of 18 months.

CONCLUSION

Annual imaging follow-up appears reasonable in selected patients with radial scars but no atypia on DBT-guided CNB.

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.

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

AIMS

The diagnosis of radial scars/complex sclerosing lesions (RSs/CSLs) onpercutaneous biopsy carries a risk of histological underestimation. Consequently, surgical excision is often performed in order to exclude a possible associated malignancy. The aim of this study was to assess the rate of 'upgrade to carcinoma' upon subsequent surgical excision of RS/CSL cases diagnosed on vacuum-assisted large-core biopsy (VALCB). We also analysed the risk factors for upgrade in order to determine a subset of patients who could avoid surgery and benefit from conservative management with clinical and imaging follow-up.

METHODS AND RESULTS

This was a retrospective observational single-centre study on 174 consecutive RS/CSL cases diagnosed on VALCB from May 2008 to October 2015. Univariate analysis was performed to identify clinical, radiological and histological risk factors for upgrade. Surgical excision was performed following VALCB diagnosis of 88 RS/CSL cases with or without associated atypia. The overall rate of surgical upgrade to carcinoma was 9.1% (8/88). None of the benign biopsies without atypia was surgically upgraded. Additional to atypia, risk factors for upgrade were non-incidental finding of the RS/CSL, the mammographic appearance, and the number of fragments obtained during the biopsy procedure (P < 0.05).

CONCLUSION

We demonstrate that VALCB revealing an RS/CSL is reliable for excluding malignancy when there is no associated atypia and when radiological and histological findings are concordant. In such cases, surgery can be avoided in favour of clinical and imaging follow-up. When an RS/CSL is associated with atypia, the decision to perform surgical excision depends on other associated risk factors.

Core needle biopsy of benign, borderline and in-situ problematic lesions of the breast: Diagnosis, differential diagnosis and immunohistochemistry

Core needle biopsy (CNB) is the most common sampling technique for the histologic evaluation of breast abnormalities. Diagnosing benign proliferative, borderline and some in-situ lesions in CNB is challenging and subject to a significant degree of interobserver variability. In addition, due to the inherent limitations of CNB, "upgrading" to a more significant pathology at excision is an important consideration for some lesions. Pathologists carry a major responsibility in patient diagnosis, risk stratification and management. Familiarity with the histologic features and the clinical significance of these common and problematic lesions encountered in CNB is necessary for adequate treatment and patient follow-up. This review will focus on benign, atypical and in-situ epithelial proliferations, papillary lesions, radial sclerosing lesions, adenosis and cellular fibroepithelial lesions. Highlights of histologic features, useful strategies for accurate diagnosis, basic immunohistochemistry and management will be presented.

Digital Breast Tomosynthesis: What Have We Learned?

Digital breast tomosynthesis (DBT) is increasingly recognized as a superior breast imaging technology compared with 2D digital mammography (DM) alone. Accumulating data confirm increased sensitivity and specificity in the screening setting, resulting in higher cancer detection rates and lower abnormal interpretation (recall) rates. In the diagnostic environment, DBT simplifies the diagnostic work-up and improves diagnostic accuracy. Initial concern about increased radiation exposure resulting from the DBT acquisition added onto a 2D mammogram has been largely alleviated by the development of synthesized 2D mammography (SM). Continued research is underway to reduce artifacts associated with SM, and improve its comparability to DM. Breast cancers detected with DBT are most often small invasive carcinomas with a preponderance for grade 1 histology and luminal A molecular characteristics. Recent data suggest that higher-grade cancers are also more often node negative when detected with DBT. A meta-analysis of early single-institution studies of the effect of DBT on interval cancers has shown a modest decrease when multiple data sets are combined. Because of the greater conspicuity of lesions on DBT imaging, detection of subtle architectural distortion is increased. Such findings include both spiculated invasive carcinomas and benign etiologies such as radial scars. The diagnostic evaluation of architectural distortion seen only with DBT can pose a challenge. When no sonographic correlate can be identified, DBT-guided biopsy and/or localization capability is essential. Initial experience with DBT-guided procedures suggests that DBT biopsy equipment may improve the efficiency of percutaneous breast biopsy with less radiation.

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.

Core Needle Biopsy of the Breast: An Evaluation of Contemporary Data

Benign and atypical lesions associated with breast cancer risk are often encountered in core needle biopsies (CNBs) of the breast. For these lesions, the rate of "upgrade" to carcinoma in excision specimens varies widely in the literature. Many CNB studies are limited by a lack of radiological-pathological correlation, consistent criteria for excision, and clinical follow-up for patients who forego excision. This article highlights contemporary diagnostic criteria and outcome data that would support an evidence-based approach to the management of these nonmalignant lesions of the breast diagnosed 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.

Mammographically Occult Asymptomatic Radial Scars/Complex Sclerosing Lesions at Ultrasonography-Guided Core Needle Biopsy: Follow-Up Can Be Recommended

An increasing number of radial scars are detected by ultrasound (US), but their management is controversial. This study investigated the upgrade rate in mammographically occult radial scars/complex sclerosing lesions without epithelial atypia at US-guided 14-gauge core needle biopsy in asymptomatic patients. Nineteen mammographically occult benign radial scars/complex sclerosing lesions (median size, 7 mm; range, 3-23 mm) were included. Patients underwent surgical excision (n = 10) or vacuum-assisted excision, with follow-up US at least 6 mo after benign vacuum-assisted excision results (n = 8), or underwent US follow-up for 2 y after core needle biopsy (n = 1). Any cases with change in diagnosis to high-risk lesions or malignancy at excision were considered upgrades. The upgrade rate was 0.0%. Based on US findings, 15.8% (3/19) were Breast Imaging Reporting and Data System (BI-RADS) category 3, 68.4% (13/19) were BI-RADS category 4a and 15.8% (3/19) were BI-RADS category 4b. Follow-up with US can be considered for mammographically occult benign radial scar/complex sclerosing lesions diagnosed by US core needle biopsy in asymptomatic patients.

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

The purpose of this study is to obtain a consensus for the therapy of B3 lesions. The first International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions) including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL), benign phyllodes tumors (PT), and radial scars (RS) took place in January 2016 in Zurich, Switzerland organized by the International Breast Ultrasound School and the Swiss Minimally Invasive Breast Biopsy group-a subgroup of the Swiss Society of Senology. Consensus recommendations for the management and follow-up surveillance of these B3 lesions were developed and areas of research priorities were identified. The consensus recommendation for FEA, LN, PL, and RS diagnosed on core needle biopsy or vacuum-assisted biopsy (VAB) is to therapeutically excise the lesion seen on imaging by VAB and no longer by open surgery, with follow-up surveillance imaging for 5 years. The consensus recommendation for ADH and PT is, with some exceptions, therapeutic first-line open surgical excision. Minimally invasive management of selected B3 lesions with therapeutic VAB is acceptable as an alternative to first-line surgical excision.

Practical Considerations in Breast Papillary Lesions: A Review of the Literature

Context.—Diagnosis of papillary breast lesions, especially in core biopsies, is challenging for most pathologists, and these lesions pose problems for patient management. Distinction between benign, premalignant, and malignant components of papillary lesions is challenging, and the diagnosis of invasion is problematic in lesions that have circumscribed margins. Obtaining a balance between overtreatment and undertreatment of these lesions is also challenging.

Objectives.—To provide a classification and a description of the histologic and immunohistochemical features and the differential diagnosis of papillary breast lesions, to provide an update on the molecular pathology of papillary breast lesions, and to discuss the recommendations for further investigation and management of papillary breast lesions. This review provides a concise description of the histologic and immunohistochemical features of the different papillary lesions of the breast.

Data Sources.—The standard pathology text books on breast pathology and literature on papillary breast lesions were reviewed with the assistance of the PubMed database (http://www.ncbi.nlm.nih.gov/pubmed).

Conclusions.—Knowledge of the clinical presentation, histology, immunoprofile, and behavior of papillary breast lesions will assist pathologists with the diagnosis and optimal management of patients with papillary breast lesions.

Radial scars diagnosed on breast core biopsy: Frequency of atypia and carcinoma on excision and implications for management

AIMS

The risk of finding carcinoma in excisions following a core needle biopsy diagnosis of radial scar is not well defined and clinical management is variable. The aim of this study is to determine the frequency of high-risk lesions, ductal carcinoma in situ, and invasive carcinoma in excisions following a core biopsy diagnosis of radial scar.

METHODS AND RESULTS

Dedicated breast pathologists and radiologists correlated the histologic and radiologic findings and categorized radial scars as the target lesion or an incidental finding. High-risk lesions were defined as atypical hyperplasia or classical lobular carcinoma in situ. Of the 79 radial scars identified over a 14-year period, 22 were associated with atypia or carcinoma in the core biopsy. Thirty-seven (37) of the 57 benign radial scars underwent excision with benign findings in 30 (81%), high-risk lesions in six (16%), and flat epithelial atypia in one (3%). There were no upgrades to carcinoma. One patient with a benign radial scar developed a 3-mm focus of intermediate-grade estrogen receptor-positive ductal carcinoma in situ in the same quadrant of the ipsilateral breast 72 months after excision. One patient with an incidental un-excised benign radial scar was diagnosed with ductal carcinoma in situ at a separate site of suspicious calcifications.

CONCLUSIONS

In this series, none of the benign radial scars was upgraded to carcinoma. Radial scar was the targeted lesion in all cases with high-risk lesions on excision. Surgical excision may not be mandatory for patients with benign incidental radial scars on core biopsy.

Isolated radial scar diagnosis by core-needle biopsy: Is surgical excision necessary?

Purpose

Radial scar and radial sclerosis (RS) are considered benign breast lesions with proliferative features. There is sparse literature on frequency of cancer upgrade in these patients without atypical features found on image-guided needle biopsy. This study retrospectively reviews cases of isolated RS diagnosed on needle biopsy and evaluates the cancer upgrade after subsequent surgical excision.

Methods

We conducted a retrospective cross-sectional study of cases with an isolated RS diagnosis based on needle biopsy and subsequent surgical pathology among all patients between January 1, 2009 and December 31, 2013. Patients with concomitant atypia, lobular carcinoma in situ on core biopsy, complete excision of very small RS with needle biopsy, and radiology-pathology discordance were excluded. An upgrade from the needle biopsy of RS was defined as surgical excision pathology that revealed ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), and/or invasive lobular carcinoma (ILC).

Results

10,921 image-guided needle biopsy pathology reports were collected and 88 patients (0.81 %) were identified as having isolated RS. Of these 88 patients, 63 (72 %) underwent excision. The upgrade rate to cancer on subsequent surgical excision was 1.59 % (1/63) for DCIS; 0 % (0/63) for IDC; and 0 % (0/63) ILC. Twenty-five patients who did not undergo surgical excision had stable imaging studies with mean (±SD) 26 (±20) months follow up.

Conclusions

Isolated radial scar on needle biopsy may not warrant routine surgical excision given relatively low cancer upgrade rates. Advancement in breast imaging, pathology and multidisciplinary approaches to care may effectively guide non-surgical management of RS.

Suspicious Findings at Digital Breast Tomosynthesis Occult to Conventional Digital Mammography: Imaging Features and Pathology Findings

To review the imaging and pathologic features of a series of lesions detected at digital breast tomosynthesis (DBT), which are occult to conventional digital mammography (DM). We retrospectively reviewed 268 consecutive breast imaging reporting and data system 4 and 5 lesions imaged with both DM and DBT at our facility from July 2012 through April 2013. For each lesion, we recorded the mammographic finding, breast density, mode of biopsy, and pathology results. A total of 19 lesions were identified at DBT that were occult to DM. Sixty three percent (12/19) of these lesions were identified in dense breasts. Architectural distortion was seen in 74% (14/19) of cases and spiculated masses accounted for the remaining 26% (5/19). The positive predictive value of biopsy was 53% (10/19). Seven cases were infiltrating ductal carcinomas and three were infiltrating lobular carcinomas. High-risk lesions accounted for 47% (9/19) of the lesions, the majority of which were radial scars 67% (6/9). Eighty four percent (16/19) of the lesions underwent ultrasound guided core biopsy while the remainder underwent magnetic resonance imaging guided core biopsy. DBT may demonstrate suspicious lesions that are occult to DM, particularly in women with dense breasts. Such lesions have a high likelihood of malignancy and warrant biopsy.

Adenosquamous proliferation of the breast and low grade adenosquamous carcinoma: a common precursor of an uncommon cancer?

Low grade adenosquamous carcinoma (LGASC) is rare but commonly reported to arise in association with benign proliferative and sclerosing breast lesions which themselves may show associated sclerosing or 'adenosquamous proliferation' (ASP) resembling LGASC, but are often derided as reactive mimics or attributed to earlier biopsy. Among other benign lesions, radial sclerosing lesion (RSL) may be associated with LGASC, yet attention is typically focused on its relationship to more common forms of mammary carcinoma. This study aimed to assess the presence and extent of ASP in the context of RSL in a small cohort of 20 cases and its similarity to LGASC.Twenty consecutive breast excisions that had a principal or incidental diagnosis of RSL were reviewed. RSLs that displayed foci of ASP were further examined with immunohistochemical markers for p63, calponin, cytokeratin 5/6, oestrogen and progesterone receptors.Sixty percent of excisions contained ASP either associated with a RSL or a concurrent papilloma, which morphologically and immunohistochemically were indistinguishable from the neoplastic ducts of LGASC. RSL with and without ASP broadly corresponded to accepted definitions for 'early' and 'late' lesions, respectively. ASP corresponded to the characteristic compact branching ducts of the core or nidus of a RSL.The morphological and immunophenotypic similarity of the ASP found in RSL and papillomata to LGASC warrants serious consideration that they are a potential precursor to LGASC, which may most commonly involute given the rarity of clinically apparent LGASC. Further study including micro-dissection of foci of ASP to compare its molecular genetic profile to that of LGASC is required.

Advocating Nonsurgical Management of Patients With Small, Incidental Radial Scars at the Time of Needle Core Biopsy: A Study of 77 Cases

Context

Radial scars are benign sclerosing lesions that are routinely excised when diagnosed in a needle core biopsy. Optimal management for patients with incidental and small (≤5 mm) radial scars is uncertain.

Objective

To assess pathologic upgrade of radial scars diagnosed in needle core biopsy samples and identify a subset of patients who could benefit from conservative management.

Design

Patients with a diagnosis of radial scar in a needle core biopsy who underwent excision of the biopsied area were identified. Radial scars greater than 5 mm in size and those with coexisting atypia, carcinoma, and papillary lesions were excluded. After histologic-radiographic correlation, rates of pathologic upgrade were assessed.

Results

Seventy-seven radial scars diagnosed in 66 patients were included. Overall, 9 of 77 (12%) showed upgrade to a high-risk lesion (6 lobular carcinoma in situ, 2 atypical ductal hyperplasia, 1 atypical lobular hyperplasia), while none (0%) showed upgrade to invasive carcinoma or ductal carcinoma in situ. One of 22 incidental radial scars (4.5%) showed upgrade on excision versus 6 of 36 (16.7%) for radial scars considered to be the radiographic target (P = .23). Older age was associated with upgrade (P &lt; .001).

Conclusions

No incidental or small (≤5 mm) radial scars excised revealed invasive carcinoma or ductal carcinoma in situ on excision. Provided there is good pathologic-radiologic concordance, it appears reasonable for these patients to be managed conservatively.

High-risk lesions at MRI-guided breast biopsy: frequency and rate of underestimation

OBJECTIVE

The purpose of this article is to determine the underestimation rate of high-risk lesions diagnosed at MRI-guided breast biopsy.

MATERIALS AND METHODS

This was a retrospective review of 446 MRI-guided breast biopsies from January 2006 through December 2010. Data were collected on examination indication, lesion size and type, and pathology results. Biopsies were performed with a 9-gauge vacuum-assisted device. Biopsy results of atypical ductal hyperplasia (ADH), papillary lesion, radial scar, lobular neoplasia, and atypia were identified and compared with final excisional pathology results. Underestimation rates were calculated and data were compared by patient and lesion characteristics using chi-square analysis.

RESULTS

Of the 446 MRI-guided biopsies, 96 (21.5%) were high-risk lesions. Forty-two of 96 lesions (44%) were masses, and 54 (56%) showed nonmass enhancement. Twenty of 96 lesions (20.8%) were ADH, nine (9.4%) were lobular neoplasia, 27 (28.1%) were papillary lesions, 20 (20.8%) were radial scar, and 20 (20.8%) were other atypias. Sixty-nine of 96 lesions (71.9%) had surgical excisional pathology results available. Sixteen of 69 (23.2%) lesions were upgraded to malignancy; 11 of the 16 (68.8%) were upgraded to ductal carcinoma in situ (DCIS) and five (31.2%) were upgraded to invasive carcinoma. The underestimation rate was 31.6% (6/19) for ADH, 5.9% (1/17) for papillary lesions, 23.1% (3/13) for radial scar, 28.6% (2/7) for lobular neoplasia, and 30.8% (4/13) for other atypias (p = 0.43). There was no statistically significant difference in underestimation rate by lesion type, size, or history of newly diagnosed breast cancer.

CONCLUSION

MRI-guided breast biopsy yielded high-risk lesions in 21.5% of cases, and the underestimation rate was 23.2%. No patient or lesion characteristics correlated with underestimation rate.

Surgical excision of radial scars diagnosed by core biopsy may help predict future risk of breast cancer

Radial scars (RS's) are benign breast lesions known to be associated with carcinomas and other high-risk lesions (HRL's). The upgrade rate to carcinoma after core biopsy revealing RS is 0-40 %. We sought to determine the outcomes of RS with and without HRL diagnosed by core biopsy. Patients who underwent core biopsy revealing RS without carcinoma at our institution between 1/1996 and 11/2012 were identified from a surgical pathology database. Retrospective chart review was utilized to classify patients as RS-no HRL or RS-HRL. HRL was defined as ADH, LCIS, and/or ALH. We determined upgrade rate to carcinoma at surgical excision, and upgrade to HRL for RS-no HRL patients. Univariate analysis was performed to identify risk factors for upgrade in RS-no HRL patients. 156 patients underwent core biopsy revealing RS, 131 RS-no HRL (84 %), and 25 RS-HRL (16 %). The overall rate of upgrade to invasive carcinoma was 0.8 % (1/124). 1.0 % (1/102) of RS-no HRL and 13.6 % (3/22) of RS-HRL patients were upgraded to DCIS (P = 0.0023). The upgrade of RS-no HRL to HRL at excision was 21.6 % (22/102). By univariate analysis, RS-no HRL with radiologic appearance of a mass/architectural distortion had a significantly higher rate of upgrade to HRL or carcinoma compared with calcifications (P = 0.03). Excision of RS to rule out associated invasive carcinoma is not warranted, given a <1 % rate of upgrade at excision. However, excision to evaluate for non-invasive cancer or HRL may be considered to help guide clinical decision-making about use of chemoprevention.

[Diagnostics of benign ductal epithelial cell proliferation of the breast in biopsy material]

The pathological evaluation of radiological or sonographical abnormalities by needle core biopsy of the breast frequently involves the differential diagnosis of benign epithelial cell proliferations. The lesions to be considered include usual type and atypical ductal epithelial cell hyperplasia, columnar cell changes including flat epithelial cell atypia, the spectrum of hyperplastic and atypical apocrine epithelial cell proliferations and papillary lesions. This review provides an overview of the diagnostic criteria, the current terminology and the differential diagnosis of these lesions. The clinical management and the prognosis of the lesions are discussed.

Radiologic-pathologic correlation at breast MR imaging: what is the appropriate management for high-risk lesions?

Breast magnetic resonance (MR) imaging is increasingly performed for a variety of indications, most commonly with the goal of detecting breast cancer. Percutaneous biopsy (usually under MR guidance or ultrasound if there is a correlating finding) is commonly used to evaluate suspicious imaging findings detected on MR imaging with the goal of identifying malignancy. It is important to be familiar with the characteristics and management of high-risk lesions detected or biopsied under MR guidance. This review focuses on the appearance of a variety of breast lesions detected on MR imaging that require excision with focus on pathologic correlation.

The radial scar of the breast diagnosed at core needle biopsy

The radial scar (RS) or complex sclerosing lesion (CSL) of the breast represents a management dilemma on diagnosis at breast core needle biopsy because of the risk of associated malignancy identified only upon surgical excision. To determine our experience, we retrospectively reviewed core needle biopsies performed at the Darlene G. Cass Breast Imaging Center from 2006 to 2011, identifying 67 patients with RS or CSL, and correlated histology at excisional biopsy with core biopsy results. Of the 67 cases, 6 (9%) were associated with malignancy at surgical excision. The average size of the RS or CSL was 1.42 cm. In conclusion, RS or CSL diagnosed at core needle biopsy still warrants surgical excision because of the significant percentage (9%) of cases with associated malignancy.

Role of core needle biopsy in the treatment of radial scar

Invasive tumor or ductal carcinoma in situ occur in radial sclerosing lesions in one third of the cases therefore, surgical excision is mandatory. Forty-five patients with radial scar morphology were examined. Ultrasound guided fine-needle aspiration biopsy (FNAB) and core biopsy (CB) were performed in all cases. The postoperative pathological findings were compared to the results of preoperative biopsies. Sensitivity of preoperative percutaneous biopsies (FNAB and CB) was 17.6% and 70.6%, false-negative rate was 82.4% with FNAB and 29.4% with CB. The negative predictive value was 48.1% and 84.8% respectively. Had we done preoperative cytology only, we would have had to perform a two-step procedure (sentinel lymph node biopsy) in 7 patients (15.6%), while with preoperative core biopsy it has decreased to 2 patients (4.4%). Preoperative CB in small radial stellate lesions is recommended to achieve accurate diagnosis in order to avoid a two-step surgical procedures.

Magnetic resonance imaging of radial sclerosing lesions (radial scars) of the breast

PURPOSE

To identify magnetic resonance (MR) imaging (MRI) features of radial sclerosing lesions (RSLs) of the breast.

METHODS AND MATERIALS

The radiologic and pathologic records for 4629 consecutive patients undergoing MR examinations of the breast were retrospectively reviewed. Patients who received a pathologic diagnosis of RSL without atypia or carcinoma at surgical excision were identified. The MR images were evaluated according to the BI-RADS-MRI lexicon by two experienced breast radiologists. The frequency of morphologic and kinetic patterns and of BI-RADS-MRI assessment categories was calculated.

RESULTS

Twenty-nine patients with 29 surgically excised RSL were identified. Nine (31%) RSL were MR-occult; the remaining 20 (69%) RSL presented as masses (10/20, 50%), architectural distortions (5/20, 25%), non-mass lesions (4/20, 20%), and focus (1/20, 5%). Kinetic analysis was performed in 18 RSL: enhancement features were benign in 9 (50%) cases, suspicious in 7 (39%) cases and indeterminate in 2 (11%) cases. Twelve (41%) MR examinations were assessed as suspicious (BI-RADS-MRI 4 and 5), and 17 (59%) as negative (BI-RADS-MRI 1) or benign (BI-RADS-MRI 2 and 3).

CONCLUSION

RSLs are often visualized on MR imaging. Just as in mammography and sonography, RSL can have variable morphologic and kinetic features, and not infrequently they can mimic invasive carcinoma of the breast.

Radial scar without associated atypical epithelial proliferation on image-guided 14-gauge needle core biopsy: analysis of 49 cases from a single-centre and review of the literature

The purpose of this study was to evaluate the reliability of image-guided 14-gauge needle core biopsy in the diagnosis of radial scar without associated atypical epithelial proliferation, by comparison with definitive histological diagnosis on surgical excision. The records of 8792 consecutive image-guided 14-gauge needle core biopsy of the breast performed from January 1996 to December 2009 were reviewed. Forty-nine cases of radial scar without associated atypical epithelial proliferation were identified and compared with definitive histological diagnosis on surgical excision. The definitive histological diagnosis on surgical excision confirmed the results of image-guided 14-gauge needle core biopsy in 36 of 49 cases (73.5%), in 9 cases (18.3%) radial scar was associated with atypical epithelial proliferation, while 4 cases out of 49 cases were upgraded to carcinoma (3 cases of ductal carcinoma in situ and one case of invasive lobular carcinoma), with an underestimation rate of 8.2%. A diagnosis of radial scar without associated atypical epithelial proliferation on image-guided 14-gauge needle core biopsy does not exclude a malignancy on surgical excision; consequently during the multidisciplinary discussion further assessment by surgical excision or vacuum-assisted excision, as recently reported, needs to be considered to obtain a definitive histological diagnosis.

A review of needle core biopsy diagnosed radial scars in the Welsh Breast Screening Programme

INTRODUCTION

Radial scars are benign breast lesions; their appearance on mammography may, however, mimic carcinoma. Needle core biopsy is performed for pre-operative diagnosis and, currently in Wales, all lesions with benign biopsy results are surgically excised. We have reviewed all cases of needle core biopsy-diagnosed radial scars from the Welsh breast screening programme, Breast Test Wales (BTW), and investigated the outcome of radial scars based on histology from surgical excision in order to evaluate the appropriateness of the current management of these lesions in Wales.

PATIENTS AND METHODS

All needle core biopsy diagnosed radial scars were identified from the BTW screening database from the start of screening in 1989 until the end of 2007.

RESULTS

A total of 118 patients were diagnosed with radial scars on needle core biopsy; two patients had bilateral radial scars. Median patient age was 54 years (range, 49-68 years). Ninety-five lesions (79%) were thought to be pure radial scars on needle core biopsy; however, only 81 pure radial scars were identified on excision biopsy histology. Carcinoma was present in seven patients and ductal carcinoma in situ in nine patients at excision biopsy. In two patients, the cancers occurred in lesions reported as pure radial scars on needle core biopsy. Twenty-two lesions showed atypical ductal or lobular hyperplasia (ADH/ALH) or both on excision biopsy; 14 of these lesions were classed as pure radial scars by needle core biopsy.

CONCLUSIONS

All core biopsy diagnosed radial scars, presenting as screen detected abnormalities, should be excised due to their association with premalignant and malignant conditions.

Radial scars without atypia diagnosed at imaging-guided needle biopsy: how often is associated malignancy found at subsequent surgical excision, and do mammography and sonography predict which lesions are malignant?

OBJECTIVE

The purposes of our study were to evaluate the surgical outcome of cases of radial scar without atypia diagnosed at imaging-guided percutaneous needle biopsy and to determine whether the mammographic and sonographic features are able to predict which lesions will be upgraded to malignancy at surgical excision.

MATERIALS AND METHODS

The records of 4,458 consecutive imaging-guided biopsies were retrospectively reviewed. Surgical excision results were available in 62 cases in which radial scar was the highest-risk lesion at stereotactically guided or sonographically guided biopsy. The mammographic and sonographic images and surgical findings were reviewed. The underestimation rate of malignancy of percutaneous biopsy was calculated. Differences in mammographic and sonographic appearances between radial scars with and without associated malignancy were evaluated using the Fisher's exact test.

RESULTS

The percutaneous malignancy underestimation rate was 8% (5/62): 9% (4/43) for sonography guided 14-gauge biopsies and 5% (1/19) for stereotactically guided 11-gauge vacuum-assisted biopsies (p = 1.000). Mammographic and sonographic appearances were not significantly different between radial scars with and those without associated malignancy.

CONCLUSION

A percutaneous diagnosis of a radial scar does not exclude associated malignancy at surgical excision. Mammographic and sonographic features of a lesion diagnosed as a radial scar at percutaneous imaging-guided biopsy do not predict which lesions will have associated malignancy at surgery. Therefore, all patients with percutaneous diagnosis of a radial scar should undergo surgical excision regardless of mammographic and sonographic appearances, until further criteria can be determined.

Typical atypical findings on dynamic MRI of the breast

Dynamic contrast enhanced magnetic resonance imaging (DCE MRI) of the breast has become an important tool to detect and characterize breast disease. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS(®)) provides a standardized vocabulary for describing the morphologic features and contrast kinetics of breast lesions. However, some lesions may show morphologic and dynamic MR features not consistent with their histologic nature resulting in incorrect categorization as malignant or benign. Another cause of diagnostic problems is artifacts. Thus correct interpretation of dynamic MRI of the breast demands knowledge of the most common pitfalls encountered in clinical practice. A pictorial overview of these is presented, with particular reference to the differentiation of malignant tumors from benign lesions.

Update on percutaneous needle biopsy of nonmalignant breast lesions

Certain nonmalignant lesions encountered on percutaneous breast biopsies pose dilemmas with regard to the most appropriate clinical management subsequent to needle biopsy (ie, surgical excision vs. follow-up). These lesions include columnar cell lesions, atypical ductal hyperplasia, lobular neoplasia, papillary lesions, radial scars, fibroepithelial lesions, and mucocele-like lesions. As minimally invasive diagnostic procedures are now standard it is more important than ever to be aware of the limitations of percutaneous biopsy, particularly with regard to apparently benign lesions because of the risk that the radiologically detected lesion may harbor malignant disease not represented in the biopsy specimen. This underscores the importance of radiologic-pathologic correlation. Increasingly, radiologists are adopting vacuum-assisted devices using larger gauge needles. The changing practices among radiologists are reflected in recent studies which have enriched the literature. In addition, magnetic resonance imaging is being used more frequently in breast imaging, resulting in pathologists more often encountering benign biopsies with uncertain imaging correlation. These changes prompted evaluation of the recent literature and its possible effect on management concerns. This review focuses on management issues following the diagnosis of nonmalignant lesions diagnosed on percutaneous breast biopsy and highlights imaging terms commonly used in breast radiology reports to facilitate accurate radiologic-pathologic correlation.

Vacuum-assisted excision of breast lesions of uncertain malignant potential (B3) - an alternative to surgery in selected cases

To assess whether vacuum-assisted excision (VAE) is a safe alternative to surgery in the treatment of breast lesions of uncertain malignant potential (B3) in which no atypia is present on needle core biopsy (NCB). Forty two VAE procedures were performed for B3 lesions. Twenty four (57%) were papillary lesions. Eighteen (43%) were radial scars. Two patients (4.7%) were upgraded to carcinoma at VAE. Two patients with papillary lesions went on to develop cancer in the same breast (at 24 and 41 months post VAE). No cancer developed in the radial scar group. Eight patients (19%) had surgery - four for carcinoma, two for radial scars missed at VAE excision and two for symptomatic papillomatosis. Follow-up mammography after VAE of radial scars often showed residual distortion. VAE can be a safe alternative to surgery in the treatment of B3 lesions without atypia, providing thorough multidisciplinary discussion has taken place.

Management of radial sclerosing lesions of the breast diagnosed using percutaneous vacuum-assisted core needle biopsy: recommendations for excision based on seven years' of experience at a single institution

BACKGROUND

Radial sclerosing lesions (RSLs) of the breast are benign lesions that can mimic carcinoma on mammography and are frequently associated with malignancy. Guidelines for the selection of patients with RSL on core needle biopsy who require surgical excision are not well defined. We describe the clinical management of RSL diagnosed using a percutaneous vacuum-assisted 9- or 11-gauge stereotactically guided core needle biopsy (SCNB) device.

METHODS

We retrospectively evaluated data on patients with mammographically detected RSLs sampled by SCNB between 2001 and 2007. Demographic data, the size and type of lesion and histological findings were correlated with subsequent surgical excision data. Clinical and radiological follow-up data were collected.

RESULTS

Among 80 patients with RSLs, 19 underwent surgical excision, and 61 had mammographic surveillance only. RSLs associated on imaging with an underlying architectural distortion were more frequently excised than those associated with calcifications (P = 0.003). The presence of residual calcifications/architectural distortion on post-biopsy mammogram significantly correlated with subsequent excision (P = 0.00003). Proliferative and/or atypical RSLs were more often excised than nonproliferative RSLs (P = 0.00001). In two patients, proliferative RSL was upgraded to atypical RSL on excision. Clinical and mammographic follow-up for a mean of 32 months (standard deviation, ± 23) in the group without excision showed no cancer.

CONCLUSIONS

Architectural distortion on imaging, residual abnormality on post-biopsy mammogram and the presence of proliferative changes and/or epithelial atypia on SCNB were parameters leading to increased performance of surgical excision in our series. No diagnoses were upgraded to malignancy after excision of RSLs, suggesting that more extensive sampling by a 9- or 11-gauge SCNB device, followed by meticulous correlation of radiological and pathological findings and close clinical/radiological follow-up, could obviate surgical excision in the majority of RSL cases without associated atypia on SCNB.