Incidence of breast cancer in patients with pure flat epithelial atypia diagnosed at core-needle biopsy of the breast

Imaging Characteristics of and Multidisciplinary Management Considerations for Atypical Ductal Hyperplasia and Flat Epithelial Atypia: Review of Current Literature

High-risk lesions of the breast are frequently encountered in percutaneous biopsy specimens. While benign, these lesions have historically undergone surgical excision due to their potential to be upgraded to malignancy. However, there is emerging evidence that a tailored management approach should be considered to reduce overtreatment of these lesions. Flat epithelial atypia (FEA) and atypical ductal hyperplasia (ADH) are two of the most commonly encountered high-risk lesions. FEA has been shown to have a relatively low rate of progression to malignancy, and some guidelines are now recommending observation over routine excision in select cases. Selective observation may be reasonable in cases where the target lesion is small and completely removed at biopsy and when there are no underlying risk factors, such as a history of breast cancer or genetic mutation or concurrent ADH. ADH has the highest potential upgrade rate to malignancy of all the high-risk lesions. Most society guidelines continue to recommend surgical excision of this lesion. More recently, some literature suggests that ADH lesions that appear completely removed at biopsy, involve limited foci (less than two or three) with no necrosis or significant atypia, manifest as a small group of mammographic calcifications, or demonstrate no enhancement at MRI may be reasonable for observation. Ultimately, management of all high-risk lesions must be based on a multidisciplinary approach that considers all patient, radiologic, clinical, and histopathologic factors. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Are Columnar Cell Lesions the Earliest Non-Obligate Precursor in the Low-Grade Breast Neoplasia Pathway?

Columnar cell lesions (CCLs) of the breast comprise a spectrum of morphologic alterations of the terminal duct lobular unit involving variably dilated and enlarged acini lined by columnar epithelial cells. The World Health Organization currently classifies CCLs without atypia as columnar cell change (CCC) and columnar cell hyperplasia (CCH), whereas flat epithelial atypia (FEA) is a unifying term encompassing both CCC and CCH with cytologic atypia. CCLs have been increasingly recognized in stereotactic core needle biopsies (CNBs) performed for the assessment of calcifications. CCLs are believed to represent the earliest non-obligate precursor of low-grade invasive breast carcinomas as they share molecular alterations and often coexist with entities in the low-grade breast neoplasia pathway. Despite this association, however, the risk of progression of CCLs to invasive breast carcinoma appears low and may not exceed that of concurrent proliferative lesions. As the reported upgrade rates of pure CCL/FEA when identified as the most advanced high-risk lesion on CNB vary widely, the management of FEA diagnosed on CNB remains controversial. This review will include a historical overview of CCLs and will examine histologic diagnostic criteria, molecular alterations, prognosis and issues related to upgrade rates and clinical management.

Upgrade rate of percutaneously diagnosed pure flat epithelial atypia: systematic review and meta-analysis of 1,924 lesions

CONTEXT

Management remains controversial due to the risk of upgrade for malignancy from flat epithelial atypia (FEA). Data about the frequency and malignancy upgrade rates are scant. Namely, observational follow-up is advised by many studies in cases of pure FEA on core biopsy and in the absence of an additional surgical excision. For cases of pure FEA, the American College of Surgeons no longer recommends surgical excision but rather recommends observation with clinical and imaging follow-up.

OBJECTIVES

The aim of this study is to perform a systematic review and meta-analysis to calculate the pooled upgrade of pure FEA following core needle biopsies.

METHODS

A search of MEDLINE and Embase databases were conducted in December 2020. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. A fixed- or random-effects model was utilized. Heterogeneity among studies was estimated by utilizing the I2 statistic and considered high if the I2 was greater than 50%. The random-effects model with the DerSimonian and Laird method was utilized to calculate the pooled upgrade rate and its 95% confidence interval.

RESULTS

A total of 1924 pure FEA were analyzed among 59 included studies. The overall pooled upgrade rate to malignancy was 8.8%. The pooled upgrade rate for mammography only was 8.9%. The pooled upgrade rate for ultrasound was 14%. The pooled upgrade rate for mammography and ultrasound combined was 8.8%. The pooled upgrade rate for MRI-only cases was 27.3%.

CONCLUSIONS

Although the guidelines for the management of pure FEA are variable, our data support that pure FEA diagnosed at core needle biopsy should undergo surgical excision since the upgrade rate >2%.

High-risk lesions of the breast: concurrent diagnostic tools and management recommendations

Breast lesions with uncertain malignant behavior, also known as high-risk or B3 lesions, are composed of a variety of pathologies with differing risks of associated malignancy. While open excision was previously preferred to manage all high-risk lesions, tailored management has been increasingly favored to reduce overtreatment and spare patients from unnecessary anxiety or high healthcare costs associated with surgical excision. The purpose of this work is to provide the reader with an accurate overview focused on the main high-risk lesions of the breast: atypical intraductal epithelial proliferation (atypical ductal hyperplasia), lobular neoplasia (including the subcategories lobular carcinoma in situ and atypical lobular hyperplasia), flat epithelial atypia, radial scar and papillary lesions, and phyllodes tumor. Beyond merely presenting the radiological aspects of these lesions and the recent literature, information about their potential upgrade rates is discussed in order to provide a useful guide for appropriate clinical management while avoiding the risks of unnecessary surgical intervention (overtreatment).

Upgrade Rate of Pure Flat Epithelial Atypia Diagnosed at Core Needle Biopsy: A Systematic Review and Meta-Analysis

Purpose

To perform a systematic review and meta-analysis to calculate the pooled upgrade rate of pure flat epithelial atypia (FEA) diagnosed at core needle biopsy (CNB).

Materials and Methods

A PubMed and Embase database search was performed in December 2019. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Study quality and publication bias were assessed. The upgrade rate of pure FEA to cancer, invasive carcinoma, and ductal carcinoma in situ (DCIS), as well as the co-occurrence rate of atypical ductal hyperplasia (ADH), with 95% CIs were calculated. A random effect model was used to integrate the proportions and their corresponding 95% CI. Study heterogeneity was calculated using τ² and I ² .

Results

A total of 2482 cases of pure FEA across 42 studies (mean age range, 46-59 years) met inclusion criteria to be analyzed. Significant study heterogeneity was identified (τ² = 0.001, I ² = 67%). The pooled upgrade rates reported for pure FEA were 5% (95% CI: 3%, 6%) for breast cancer, 1% (95% CI: 0%, 2%) for invasive carcinoma, and 2% (95% CI: 1%, 3%) for DCIS. When more than 90% of calcifications were removed at CNB, the pooled upgrade rate was 0% (95% CI: 0%, 2%). The pooled co-occurrence rate of ADH at surgical excision was 17% (95% CI: 12%, 21%). Study quality was medium to high with a risk of publication bias (P < .01).

Conclusion

Pure FEA diagnosed at CNB should be surgically excised due to the pooled upgrade rate of 5% for breast cancer. If more than 90% of the targeted calcifications are removed by CNB for pure FEA, close imaging follow-up is recommended.Keywords: Biopsy/Needle Aspiration, Breast, MammographySupplemental material is available for this article.© RSNA, 2021.

Performance of a clinical and imaging-based multivariate model as decision support tool to help save unnecessary surgeries for high-risk breast lesions

PURPOSE

To investigate the performance of an imaging and biopsy parameters-based multivariate model in decreasing unnecessary surgeries for high-risk breast lesions.

METHODS

In an IRB-approved study, we retrospectively reviewed all high-risk lesions (HRL) identified at imaging-guided biopsy in our institution between July 1, 2014-July 1, 2017. Lesions were categorized high-risk-I (HR-I = atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ and atypical papillary lesion) and II (HR-II = Flat epithelial atypia, radial scar, benign papilloma). Patient risk factors, lesion features, detection and biopsy modality, excision and cancer upgrade rates were collected. Reference standard for upgrade was either excision or at least 2-year imaging follow-up. Multiple logistic regression analysis was performed to develop a multivariate model using HRL type, lesion and biopsy needle size for surgical cancer upgrade with performance assessed using ROC analysis.

RESULTS

Of 699 HRL in 652 patients, 525(75%) had reference standard available, and 48/525(9.1%) showed cancer at surgical excision. Excision (84.5% vs 51.1%) and upgrade (17.6%vs1.8%) rates were higher in HR-I compared to HR-II (p < 0.01). In HR-I, small needle size < 12G vs ≥ 12G [32.1% vs 13.2%, p < 0.01] and less cores [< 6 vs ≥ 6, 28.6%vs13.7%, p = 0.01] were significantly associated with higher cancer upgrades. Our multivariate model had an AUC = 0.87, saving 28.1% of benign surgeries with 100% sensitivity, based on HRL subtype, lesion size(mm, continuous), needle size (< 12G vs ≥ 12G) and biopsy modality (US vs MRI vs stereotactic) CONCLUSION: Our multivariate model using lesion size, needle size and patient age had a high diagnostic performance in decreasing unnecessary surgeries and shows promise as a decision support tool.

Flat Epithelial Atypia in Breast Core Needle Biopsies With Radiologic-Pathologic Concordance: Is Excision Necessary?

Flat epithelial atypia (FEA) is an alteration of terminal duct lobular units by a proliferation of ductal epithelium with low-grade atypia. No consensus exists on whether the diagnosis of FEA in core needle biopsy (CNB) requires excision (EXC). We retrospectively identified all in-house CNBs obtained between January 2012 and July 2018 with FEA. We reviewed all CNB slides and assessed radiologic-pathologic concordance. An upgrade was defined as invasive carcinoma (IC) and/or ductal carcinoma in situ in the EXC. The EXC slides of all upgraded cases were rereviewed. Out of ∼15,700 consecutive CNBs in the study period, 106 CNBs from 106 patients yielded FEA alone or with classic lobular neoplasia (LN). We excluded 52 CNBs (40 patients with prior/concurrent carcinoma and 12 without EXC). After rereview, we reclassified 14 cases (2 marked nuclear atypia, 10 focal atypical ductal hyperplasia, 2 benign). The final FEA study cohort consisted of 40 CNBs from 40 women. The CNB targeted mammographic calcifications in 36 (90%) cases, magnetic resonance imaging nonmass enhancement in 3 (8%), and 1 (2%) sonographic mass. All CNBs were deemed radiologic-pathologic concordant. FEA was present alone in 34 CNBs and with LN in 6. EXC yielded 2 low-grade IC, each spanning <2 mm, identified in tissue sections without biopsy site changes. The remaining 38 cases had no upgrade. Classic LN did not affect the upgrade. The upgrade rate of FEA was 5%; both minute, low-grade "incidental" IC. We conclude that nonsurgical management may be considered in patients without prior/concurrent carcinoma and radiologic-pathologic concordant CNB diagnosis of FEA.

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.

Flat epithelial atypia and the risk of sampling error: Determining the value of excision after image-guided core-needle biopsy

BACKGROUND

We determined the sampling error rate of flat epithelial atypia (FEA) and evaluated current guidelines recommending excisional biopsy.

METHODS

A retrospective review of consecutive excisional biopsies after image-guided core-needle biopsy identified patients with isolated FEA diagnosed between 2014 and 2018. Clinical and pathologic parameters were evaluated.

RESULTS

Twenty-five women with 27 biopsies were included. Based on pathologic review of original core specimens, 44.4% (N = 12) were accurately diagnosed as FEA. Upon excision, lesions were upgraded to ductal carcinoma in situ (N = 2) or invasive ductal carcinoma (N = 1) in 11.1% of cases. Older age, black race, hormone replacement, and calcifications in the image-guided biopsy specimen were associated with the presence of high-risk or malignant lesions in the excisional biopsy (all p ≤ 0.05).

CONCLUSIONS

In this study, FEA was frequently overcalled. However, lesions suspicious for FEA warrant excision due to their association with malignancy or high-risk lesions, which may necessitate further surgical management and/or risk-reducing strategies.

Sonographic Features of Flat Epithelial Atypia Manifesting as a Non-Mass-Like Lesion: A Case Report

Patient: Female, 47

Final Diagnosis: Flat epithelial atypia of the breast

Symptoms: —

Medication: —

Clinical Procedure: —

Specialty: Radiology

Flat epithelial atypia in directional vacuum-assisted biopsy of breast microcalcifications: surgical excision may not be necessary

The aim of this study was to analyze the clinicopathological features of patients with flat epithelial atypia, diagnosed in directional vacuum-assisted biopsy targeting microcalcifications, to identify upgrade rate to in situ ductal or invasive breast carcinoma, and determine factors predicting carcinoma in the subsequent excision. We retrospectively evaluated the histological, clinical, and mammographic features of 69 cases from 65 women, with directional vacuum-assisted biopsy-diagnosed flat epithelial atypia with or without atypical ductal hyperplasia or atypical lobular hyperplasia, which underwent subsequent surgical excision. The extent and percentage of microcalcifications sampled by directional vacuum-assisted biopsy were evaluated by mammography. All biopsy and surgical excision slides were reviewed. The age of the women ranged from 40 to 85 years (mean 57 years). All patients presented with mammographically detected microcalcifications only, except in one case that had associated architectural distortion. Extent of calcifications ranged from <1 cm (n = 47), 1-3 cm (n = 15) to > 3 cm (n = 6), and no measurement (n = 1). A mean of 11 cores (range 6-25) was obtained from each lesion. Post-biopsy mammogram revealed >90% removal of calcifications in 81% of cases. Pure flat epithelial atypia represented nearly two-thirds of directional vacuum-assisted biopsy specimens (n = 43, 62%), while flat epithelial atypia coexisted with atypical ductal hyperplasia (18 cases, 26%), or atypical lobular hyperplasia (8 cases, 12%). Upon excision, none of the cases were upgraded to in situ ductal or invasive breast cancer. In one case, however, an incidental, tubular carcinoma (4 mm) was found away from biopsy site. Excluding this case, the upgrade rate was 0%. Our study adds to the growing evidence that diagnosis of flat epithelial atypia on directional vacuum-assisted biopsy for microcalcifications as the only imaging finding is not associated with a significant upgrade to carcinoma on excision, and therefore, excision may not be necessary. Additionally, excision may not be necessary for flat epithelial atypia with atypical ductal hyperplasia limited to ≤2 terminal duct-lobular units, if at least 90% of calcifications have been removed on biopsy.

Surgical Highlights from the 40th San Antonio Breast Cancer Symposium: 5-9 December 2017, San Antonio, Texas

This year San Antonio Breast Cancer Symposium (SABCS) celebrated its 40^th anniversary. As in the past years, this year's conference was held in Henry B. Gonzalez Convention Centre, San Antonio, Texas, on 5-9 December 2017. The conference highlighted many different topic on breast cancer including basic science, translational research, local therapies, systemic therapies, survivorship, early clinical trials, and surgical topics. Even though SABCS evolved towards basic science and systemic therapy based manner in recent years, there were some important topics about local therapies and surgical approach. In this conference report, presentations and keynote talks about surgical field and local therapies will be summarised.

How Do We Approach Benign Proliferative Lesions?

PURPOSE OF REVIEW

The aim of this review is to summarize recently published literature addressing atypical ductal hyperplasia (ADH), lobular neoplasia (atypical lobular hyperplasia [ALH] and classic lobular carcinoma in situ [C-LCIS]), non-classic lobular carcinoma in situ (NC-LCIS), papillary lesions, and flat epithelial atypia (FEA).

RECENT FINDINGS

While ADH, ALN, and C-LCIS are well-established markers of an increased risk of future breast cancers, the risk implications are less clear for papillary lesions and FEA. NC-LCIS is the least well-characterized lesion, with scant published literature on its natural history and surgical management when encountered on needle biopsy. Recent data suggest that lobular neoplasia on core biopsy of a BI-RADS ≤ 4 concordant lesion does not require an excision, while ADH, atypical papillomas, and NC-LCIS should be excised. Evidence on FEA and papillomas without atypia suggests a low risk of upgrade on excision, and prospective studies on the upgrade of these lesions are ongoing.

Flat Epithelial Atypia on Core Biopsy and Upgrade to Cancer: a Systematic Review and Meta-Analysis

BACKGROUND

No consensus exists on whether flat epithelial atypia (FEA) diagnosed percutaneously should be surgically excised. A systematic review and meta-analysis of the frequency of upgrade to cancer or an atypical ductal hyperplasia (ADH) at surgical excision of FEA was performed.

METHODS

Embase, MEDLINE, Scopus, and Web of Science databases from January 2003 to November 2015 were searched. The inclusion criteria required a manuscript in English with original data on FEA diagnosed percutaneously, data including the presence or absence of other concurrent high-risk lesions, and data including outcome of cancer at surgical excision. Studies were assessed for quality, and two reviewers extracted data. Random-effects meta-analysis was used to pool estimates. The impact of study-level characteristics was assessed by stratified meta-analysis and meta-regression.

RESULTS

The inclusion criteria was met by 32 studies. A total of 1966 core needle biopsies showed pure FEA, and 1517 (77%) showed surgical excision. The proportions of patients with upgrade to cancer varied from 0 to 42%, with an overall pooled estimate of 11.1%. Heterogeneity was observed, with the greatest impact based on whether a study included cases of FEA diagnosed before 2003. With restriction of the investigation to 16 higher-quality studies, the cancer upgrade pooled estimate was 7.5% (95% confidence interval [CI], 5.4-10.4%), and the rate of invasive cancer was 3% (95% CI 1.9-4.5%). For upgrade to ADH, data from 22 studies including 937 patients were analyzed. The proportion of patients upgraded to ADH ranged from 0 to 60%, with a pooled estimate of 17.9% overall and 18.6% among high-quality studies.

CONCLUSIONS

With patient management change potential for approximately 25% of patients, this analysis supports a general recommendation for surgical excision of FEA diagnosed by core biopsy.

Vacuum-assisted stereotactic breast biopsy in the diagnosis and management of suspicious microcalcifications

PURPOSE

We aimed to present our biopsy method and retrospectively evaluate the results, upgrade rate, and follow-up findings of stereotactic vacuum-assisted breast biopsy (VABB) procedures performed in our clinic.

METHODS

Two hundred thirty-four patients with mammographically detected nonpalpable breast lesions underwent VABB using a 9 gauge biopsy probe and prone biopsy table. A total of 195 patients (median age 53 years, range 32-80 years) with 198 microcalcification-only lesions with a follow-up of at least one year were included in the study. The location of the lesion relative to the needle was determined from the postfire images, and unlike the conventional technique, tissue retrieval was predominantly performed from that location, followed by a complete 360° rotation, if needed.

RESULTS

The median core number was 8.5. Biopsy results revealed 135 benign, 24 atypical, and 39 malignant lesions. The total upgrade rate at surgery was 7.7% (6.1% for ductal carcinomas in situ and 10.5% for atypical lesions). Patients with benign lesions were followed up for a median period of 27.5 months, with no interval change. At the follow-up, scar formation was seen in 23 patients (17%); three of the scars were remarkable for resembling a malignancy.

CONCLUSION

Our biposy method is fast and practical, and it is easily tolerated by patients without compromising accuracy. Patients with a diagnosis of atypia still need to undergo a diagnostic surgical procedure and those with a malignancy need to undergo curative surgery, even if the lesion is totally excised at biopsy. VABB may leave a scar in the breast tissue, which may resemble a malignancy, albeit rarely.

Surgical implications and variability in the use of the flat epithelial atypia diagnosis on breast biopsy specimens

OBJECTIVES

Flat epithelial atypia (FEA) is a relatively new diagnostic term with uncertain clinical significance for surgical management. Any implied risk of invasive breast cancer associated with FEA is contingent upon diagnostic reproducibility, yet little is known regarding its use.

MATERIALS AND METHODS

Pathologists in the Breast Pathology Study interpreted one of four 60-case test sets, one slide per case, constructed from 240 breast biopsy specimens. An electronic data form with standardized diagnostic categories was used; participants were instructed to indicate all diagnoses present. We assessed participants' use of FEA as a diagnostic term within: 1) each test set; 2) 72 cases classified by reference as benign without FEA; and 3) six cases classified by reference as FEA. 115 pathologists participated, providing 6900 total independent assessments.

RESULTS

Notation of FEA ranged from 0% to 35% of the cases interpreted, with most pathologists noting FEA on 4 or more test cases. At least one participant noted FEA in 34 of the 72 benign non-FEA cases. For the 6 reference FEA cases, participant agreement with the case reference FEA diagnosis ranged from 17% to 52%; diagnoses noted by participating pathologists for these FEA cases included columnar cell hyperplasia, usual ductal hyperplasia, atypical lobular hyperplasia, and atypical ductal hyperplasia.

CONCLUSIONS

We observed wide variation in the diagnosis of FEA among U.S. pathologists. This suggests that perceptions of diagnostic criteria and any implied risk associated with FEA may also vary. Surgical excision following a core biopsy diagnosis of FEA should be reconsidered and studied further.

Is the outcome at surgery different when flat epithelial atypia and lobular neoplasia are found in association at biopsy?

OBJECTIVE

To assess the impact on the final outcome at surgery of flat epithelial atypia (FEA) when found concomitantly with lobular neoplasia (LN) in biopsy specimens compared with pure biopsy-proven FEA.

METHODS

The approval from the institutional review board of the CHUM (Centre Hospitalier Universitaire de Montréal) was obtained. A retrospective review of our database between 2009 and 2013 identified 81 females (mean age 54 years, range 38-90 years) with 81 FEA biopsy-proven lesions. These were pure or associated with LN only in 59/81 (73%) and 22/81 (27%) cases, respectively. Overall, 57/81 (70%) patients underwent surgery and 24/81 (30%) patients underwent mammographic surveillance with a mean follow-up of 36 months.

RESULTS

FEA presented more often as microcalcifications in 68/81 (84%) patients and were mostly amorphous in 49/68 (72%). After excluding radio pathologically discordant cases, pure FEA proved to be malignant at surgery in 1/41 (2%; 95% confidence interval 0.06-12.9). There was no statistically significant difference in the upgrade to malignancy whether FEA lesions were pure or associated to LN at biopsy (p = 0.4245); however, when paired in biopsy specimens, these lesions were more frequently associated with atypical ductal hyperplasia (ADH) at surgery than with pure FEA (p = 0.012).

CONCLUSION

Our results show a 2% upgrade rate to malignancy of pure FEA lesions. When FEA is found in association with LN at biopsy, surgical excision yields more frequently ADH than pure FEA thus warranting close surveillance or even surgical excision. Advances in knowledge: The association of LN with FEA at biopsy was more frequently associated with ADH at surgery than with pure FEA. If a biopsy-proven FEA lesion is deemed concordant with the imaging finding, when paired with LN at biopsy, careful surveillance or even surgical excision is suggested.

Upgrade rates of high-risk breast lesions diagnosed on core needle biopsy: a single-institution experience and literature review

Optimal management of high-risk breast lesions detected by mammogram yielding atypical ductal hyperplasia, flat epithelial atypia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar without atypia on core needle biopsy is controversial. This is a single-institution retrospective review of 5750 core needle biopsy cases seen over 14.5 years, including 249 (4.3%), 72 (1.3%), 50 (0.9%), 37 (0.6%), and 54 (0.9%) cases of atypical ductal hyperplasia, flat epithelial atypia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar without atypia, respectively. Patient age, radiologic characteristics, needle gauge, and excision diagnoses were recorded. Of 462 high-risk cases analyzed, 333 (72%) underwent excision. Upgrade rate to ductal carcinoma in situ, pleomorphic carcinoma in situ, or invasive mammary carcinoma was 18% for atypical ductal hyperplasia, 11% for flat epithelial atypia, 9% for atypical lobular hyperplasia, 28% for lobular carcinoma in situ, and 16% for radial scar. Carcinoma diagnosed on excision was more likely to be in situ than invasive, and if invasive, more likely to be low grade than high grade. Overall, cases that were benign (vs high risk or carcinoma) on excision were less likely to have residual calcifications after biopsy (17% vs 27%, P=0.013), and more likely to have a smaller mass size (<1 cm) (82% vs 50%, P=0.001). On subgroup analysis, atypical ductal hyperplasia cases that were benign (vs high risk or carcinoma) on excision were more likely to have smaller mass size (<1 cm) (P=0.025). Lobular neoplasia diagnosed incidentally (vs targeted) on core needle biopsy was less likely to upgrade on excision (5% vs 39%, P=0.002). A comprehensive literature review was performed, identifying 116 studies reporting high-risk lesion upgrade rates, and our upgrade rates were similar to those of more recent larger studies. Careful radiological-pathological correlation is needed to identify high-risk lesion subgroups that may not need excision.

Atypical epithelial hyperplasia of the breast: state of the art

INTRODUCTION

Atypical epithelial hyperplasia (AEH) of the breast is considered benign histological lesions with breast cancer risk. This review focuses on clinical signification and management of AEH that remains controversial.

AREAS COVERED

A review of published studies was performed using medline database. In this review, we fully describe the current evidence available. In particular, we describe 1) data from immunohistochemistry and molecular studies that suggest AEH is a precursor of breast cancer; 2) epidemiological studies demonstrate low rate of breast cancer in women with AEH; 3) surgical excision is necessary after diagnosis of AEH, such as lobular carcinoma in situ or atypical ductal hyperplasia, on core needle biopsy; 4) although current recommendations are evolving to fewer (if not no) excisions for flat epithelial with atypia and classic lobular neoplasia found on percutaneous biopsy (without radiologic indications for excision). Expert commentary: HEA management steel need prospective evidences, but recent retrospective data give some clue for less invasive management for some of HEA.

[Benign proliferative breast disease with and without atypia]

In the last few years, diagnostics of high-risk breast lesions (atypical ductal hyperplasia [ADH], flat epithelial atypia [FEA], lobular neoplasia: atypical lobular hyperplasia [ALH], lobular carcinoma in situ [LCIS], radial scar [RS], usual ductal hyperplasia [UDH], adenosis, sclerosing adenosis [SA], papillary breast lesions, mucocele-like lesion [MLL]) have increased with the growing number of breast percutaneous biopsies. The management of these lesions is highly conditioned by the enlarged risk of breast cancer combined with either an increased probability of finding cancer after surgery, either a possible malignant transformation (in situ or invasive cancer), or an increased probability of developing cancer on the long range. An overview of the literature reports grade C recommendations concerning the management and follow-up of these lesions: in case of ADH, FEA, ALH, LCIS, RS, MLL with atypia, diagnosed on percutaneous biopsies: surgical excision is recommended; in case of a diagnostic based on vacuum-assisted core biopsy with complete disappearance of radiological signal for FEA or RS without atypia: surgical abstention is a valid alternative approved by multidisciplinary meeting. In case of ALH (incidental finding) associated with benign lesion responsible of radiological signal: abstention may be proposed; in case of UDH, adenosis, MLL without atypia, diagnosed on percutaneous biopsies: the concordance of radiology and histopathology findings must be ensured. No data is available to recommend surgery; in case of non-in sano resection for ADH, FEA, ALH, LCIS (except pleomorphic type), RS, MLL: surgery does not seem to be necessary; in case of previous ADH, ALH, LCIS: a specific follow-up is recommended in accordance with HAS's recommendations. In case of FEA and RS or MLL combined with atypia, little data are yet available to differ the management from others lesions with atypia; in case of UDH, usual sclerosing adenosis, RS without atypia, fibro cystic disease: no specific follow-up is recommended in agreement with HAS's recommendations.

Flat epithelial atypia and risk of breast cancer: A Mayo cohort study

BACKGROUND

Based on its cytologic features, and its co-occurrence with atypical hyperplasia and breast cancer, flat epithelial atypia (FEA) has been proposed as a precursor lesion on the pathway to the development of breast cancer. It is often referred to as an "atypical" or high-risk lesion. However, to the authors' knowledge, the long-term risk of breast cancer in women with FEA is undefined.

METHODS

Specimens with FEA were identified among excisional breast biopsies in the Mayo Clinic Benign Breast Disease Cohort, which includes 11,591 women who had benign biopsy findings at the Mayo Clinic in Rochester, Minnesota between 1967 and 2001. Breast cancer risk among subsets of patients with FEA and nonproliferative, proliferative, and atypical hyperplasia (AH) was assessed using standardized incidence ratios (SIRs) compared with the Iowa Surveillance, Epidemiology, and End Results registry.

RESULTS

FEA was identified in 282 women (2.4%); 130 had associated AH (46%) and 152 (54%) were classified as having proliferative disease without atypia (PDWA). With median follow-up of 16.8 years, the SIR for breast cancer in patients with AH plus FEA was 4.74 (95% confidence interval [95% CI], 3.17-6.81) versus 4.23 (95% CI, 3.44-5.13) for those with AH without FEA (P = .59). The SIR for patients with PDWA plus FEA was 2.04 (95% CI, 1.23-3.19) versus 1.90 (95% CI, 1.72-2.09) for patients with PDWA without FEA (P = .76).

CONCLUSIONS

FEA is an uncommon finding in women with benign breast disease. FEA does not appear to convey an independent risk of breast cancer beyond that of the associated PDWA or AH.

Management of flat epithelial atypia on breast core biopsy may be individualized based on correlation with imaging studies

Flat epithelial atypia of the breast commonly co-exists with atypical ductal hyperplasia, lobular neoplasia, and indolent forms of invasive carcinomas such as tubular carcinoma. Most patients with pure flat epithelial atypia on core biopsy undergo surgical excision to evaluate for carcinoma in the adjacent breast tissue. Studies to date have reported varying upgrade rates with most recommending follow-up excision. These studies have often lacked detailed radiographic correlation, central review by breast pathologists and information regarding the biology of the carcinomas identified upon excision. In this study, we report the frequency of upgrade to invasive carcinoma or ductal carcinoma in situ in excision specimens following a diagnosis of pure flat epithelial atypia on core biopsy. Radiographic correlation is performed for each case and grade/receptor status of detected carcinomas is reported. Seventy-three (73) core biopsies containing pure flat epithelial atypia were identified from our files, meeting inclusion criteria for the study. In the subsequent excision biopsies, five (7%) cases contained invasive carcinoma or ductal carcinoma in situ and seventeen (23%) contained atypical ductal hyperplasia or lobular neoplasia. All of the ductal carcinoma in situ cases with estrogen receptor results were estrogen receptor positive and intermediate grade. The invasive tumors were small (pT1a) hormone receptor-positive, HER2-negative, low-grade invasive ductal or tubular carcinomas with negative sentinel lymph-node biopsies. No upgrades were identified in the 14 patients who had all of their calcifications removed by the stereotactic core biopsy. Our rate of upgrade to carcinoma, once cases with discordant imaging are excluded, is at the lower end of the range reported in the literature. Given the low upgrade rate and indolent nature of the carcinomas associated with flat epithelial atypia, case management may be individualized based on clinical and radiographic findings. Excision may not be necessary for patients without remaining calcifications following core biopsy.

Current management of lesions associated with an increased risk of breast cancer

High-risk breast lesions, which comprise benign lesions and in situ carcinomas (lobular carcinoma in situ and ductal carcinoma in situ), are clinically, morphologically, and biologically heterogeneous and are associated with an increased risk of invasive breast cancer development, albeit to varying degrees. Recognition and proactive management of such lesions can help to prevent progression to invasive disease, and might, therefore, reduce breast cancer incidence, morbidity, and mortality. However, this opportunity comes with the possibility of overdiagnosis and overtreatment, necessitating risk-based intervention. Notably, despite the progress in defining the molecular changes associated with carcinogenesis, alterations identifying the individuals with high-risk lesions that will progress to invasive carcinoma remain to be identified. Thus, until reproducible clinicopathological or molecular features predicting an individual's risk of breast cancer are found, management strategies must be defined by population-level risks as determined by models such as the Gail or IBIS models, as well as patient attitudes toward the risks and benefits of interventions. Herein, we review the contemporary approaches to diagnosis and management of high-risk breast lesions. Progress in this area will ultimately be dependent on the ability to individualize risk prediction through better definition of the key drivers in the carcinogenic process.

[Breast surgeon role in the management of high-risk breast lesions]

Diagnostics of high-risk breast lesions have increased these last years with the augmentation of breast percutaneous biopsies. They are lesions that confer an enlarged risk of breast cancer, either because of an increased probability of finding cancer after open surgery, a possible evolution toward in situ or invasive cancer, or because of an increased probability of developing breast cancer over the long term. Much progress has been made these last years in their histological diagnostic, classification and pathogenesis. Nevertheless, no consensus exists to date on the management of these "high-risk" lesions. In particular, surgical indications and follow-up modalities remain controversial for each histological type. In this review, the principal factors that could impact surgical decision and long-term follow-up are discussed with areas of controversy highlighted.

Papillary lesions of the breast: outcomes of 156 patients managed without excisional biopsy

Papillomas of the breast are benign epithelial neoplasms. Because of the low, but continued potential for malignancy, the treatment options after initial diagnosis remain controversial. The aim of this study was to analyze the clinical course of patients with papilloma who were managed by active surveillance following initial diagnosis by core needle biopsy or vacuum-assisted biopsy. This retrospective study analyzed 174 patients with 180 papillomas that were diagnosed by core needle biopsy (113 cases) or vacuum-assisted biopsy (67 cases) at the Breast Center Seefeld Zurich between February 2002 and May 2011. We excluded 24 cases that underwent excisional biopsy for removal of the lesion. Over a mean follow-up of 3.5 years, 13 further events occurred in 156 cases (8%). These events included two cases of ductal carcinoma in situ (one after 4 and one after 6 years), one case of atypical ductal hyperplasia, one radial scar, eight cases of papilloma, and one case of flat epithelial atypia. No invasive carcinomas occurred during the follow-up period. Conservative management of 156 papillary lesions with removal by vacuum-assisted biopsy and surveillance was not associated with invasive cancer over a median follow-up of 3.5 years. Therefore, this approach seems to be a safe option for the clinical management of papillary lesions.

Do columnar cell lesions exist in the male breast?

AIMS

In females, columnar cell lesions (CCLs) have been recognized as putative precursor lesions of low-grade breast cancer, but their role in male breast carcinogenesis is as yet unclear.

METHODS AND RESULTS

We reviewed surgical resections from males with breast cancer (n = 89), gynaecomastia (n = 20) and normal breast specimens from autopsies (n = 5) for the presence of CCL. In addition, we performed immunohistochemistry for cytokeratin 5/6 (CK5/6), CK14 and oestrogen receptor alpha (ER). In 19 of 89 resections (two DCIS cases and 17 invasive carcinoma), some individual ducts were found to contain cells with snouts on the luminal border but lacking further typical columnar cell lesion features. We mainly found three-layered ductal epithelium, characteristic for gynaecomastia and confirmed by immunohistochemistry. Moreover, we found a few ducts in male breast cancer sections that were clonally negative for basal cytokeratins.

CONCLUSION

We found no lesions with convincing CCL morphology at the periphery of invasive male breast cancers, in gynaecomastia or in normal male breast specimens. Although we cannot completely exclude the existence of CCLs in the male breast, these lesions seem to be very uncommon and are therefore unlikely to play a major role in male breast carcinogenesis.