Flat epithelial atypia on core needle biopsy does not always mandate excisional biopsy

Incidence of Adjacent Synchronous Ipsilateral Infiltrating Carcinoma and/or Ductal Carcinoma In Situ in Patients Diagnosed with Flat Epithelial Atypia by Core Needle Biopsy (TBCRC 034)

BACKGROUND

Flat epithelial atypia (FEA), a rare breast proliferative lesion, is often diagnosed following core biopsy (CB) of mammographic microcalcifications. In the prospective multi-institution TBCRC 034 trial, we investigate the upgrade rate to ductal carcinoma in situ (DCIS) or invasive cancer following excision for patients diagnosed with FEA on CB.

PATIENTS AND METHODS

Patients with a breast imaging reporting and data system (BI-RADS) ≤ 4 imaging abnormality and a concordant CB diagnosis of FEA were identified for excision. Upgrade rates were determined on the basis of local and central pathology review. The prespecified threshold to omit excision of FEA on CB was an upgrade rate of ≤ 3%. Sample size and confidence intervals were based on exact binomial calculation.

RESULTS

Overall, 129 patients underwent excision (median age 50 years, range 30-84 years). After local pathology review, 6/129 patients (4.7%; 95% CI 1.7-9.8%) were upgraded to invasive carcinoma (n = 3) or DCIS (n = 3) at excision. Among 116 patients with CB available for central pathology review, FEA was confirmed in 78 (67.2%, 95% CI 57.9-75.7%). Of these, only one patient was upgraded to DCIS (1.3%; 95% CI 0.03-6.9%), which was also one of the locally upgraded cases. Among the other five local upgrades, two did not have CB available for central review, two CB had ADH, and one CB had normal tissue on central review.

CONCLUSIONS

Among patients with FEA on CB, the upgrade rate was 4.7% based on local pathology review and 1.3% based on central pathology review. These findings highlight the importance of shared decision-making in the management of FEA.

Increased risk of upstage when combinations of breast lesions of uncertain malignant potential are found on core needle biopsy: The need for surgical excision

BACKGROUND

Management of breast lesions of uncertain malignant potential diagnosed at core needle biopsy (CNB) is controversial due to variable upstage rate (UR) with surgical excision (SE).

METHODS

We performed an IRB-approved retrospective analysis of adult women who underwent CNB demonstrating atypical ductal hyperplasia (ADH), flat epithelial atypia, radial scar, or intraductal papilloma then SE between 2010 and 2022. We evaluated CNB pathology for combination diagnoses (CD), defined as multiple primary lesions or primary with lobular neoplasia (LN), and surgical pathology for upstage.

RESULTS

719 patients were included. UR was 12.2% (88/719). CD experienced higher UR than pure (17.7% (45/254) vs. 9.2% (43/465), p ​= ​0.001). ADH/LN had the highest UR of all CD (34.6% (9/26), p ​= ​0.001). Increased size (15.6 vs. 10.5 ​mm, p ​< ​0.001), distance from nipple (79 vs. 66 ​mm, p ​< ​0.001), and personal history of breast cancer (p ​= ​0.04) were associated with UR.

CONCLUSIONS

CD was associated with increased UR. ADH/LN had the highest UR.

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%.

The effect of delay of excisional biopsy on upstage rate for atypical ductal hyperplasia, flat epithelial atypia, intraductal papilloma, and radial scar

PURPOSE

When Core Needle Biopsy (CNB) demonstrates Atypical Ductal Hyperplasia (ADH), Flat Epithelial Atypia (FEA), Intraductal Papilloma (IDP), or Radial Scar/Complex Sclerosing Lesion (RS), excisional biopsy (EB) is often performed to rule out underlying malignancy with upstage rates (UR) ranging between 1 and 20%. The COVID-19 pandemic led to delayed EB for many patients. We sought to evaluate whether this delay was associated with higher UR.

METHODS

We performed a retrospective analysis of women who underwent CNB and then EB for ADH, FEA, IDP, or RS between 2017 and 2021 using an IRB-approved repository. UR was evaluated by days between CNB and EB.

RESULTS

473 patients met inclusion. 55 were upstaged to cancer (11.6%). 178 patients had pure ADH on CNB and 37 were upstaged (20.8%). 50 patients had pure FEA and 3 were upstaged (6%). 132 had pure IDP and 7 were upstaged (5.3%). 98 had pure RS and 1 was upstaged (1%). 7/15 (46.7%) had a combination of diagnoses or diagnosis with palpable mass and were upstaged. Days between CNB and EB were < 60 for 275 patients (58.1%), 60-90 for 108 (22.8%), 91-120 for 43 (9.1%), and > 120 for 47 (9.9%). There was no significant difference in UR (10.9% for < 60, 14.8% for 60-90, 7% for 90-120, and 12.8% for > 120, p = 0.54). UR for ADH was clinically increased after 60 days (27.8 vs. 17.5%), but this did not reach statistical significance (p = 0.1).

CONCLUSION

Surgical delay was not associated with an increased UR.

Tomosynthesis-Guided Vacuum-Assisted Breast Biopsy of Architectural Distortion Without a Sonographic Correlate: A Retrospective Review

BACKGROUND. Digital breast tomosynthesis-guided vacuum-assisted breast biopsy (DBT VAB) allows biopsy of findings seen better or exclusively on digital breast tomosynthesis (DBT), including architectural distortion. Although architectural distortion with an associated sonographic mass correlate has a high risk of malignancy, limited data describe the radiologic-pathologic correlation of tomosynthesis-detected architectural distortion without a sonographic correlate. OBJECTIVE. This study evaluates the malignancy rate of architectural distortions without a sonographic correlate that undergo DBT VAB and provides radiologic-pathologic correlation for benign, high-risk, and malignant entities that are associated with architectural distortion. METHODS. We retrospectively reviewed imaging, as well as pathology slides and/or reports, for DBT VABs performed for architectural distortion without a sonographic correlate at a single institution between June 1, 2017, and January 15, 2020. According to the correlative histopathology, cases were categorized as benign, high risk, or malignant, and specific histopathologic diagnoses were summarized. RESULTS. During the study period, 142 patients (mean age, 59 years) underwent DBT VAB for 151 unique architectural distortions without a sonographic correlate. DBT VAB revealed a malignant diagnosis in 27 (18%), a high-risk lesion in 50 (33%), and a benign diagnosis in 74 (49%). Two cases of atypical ductal hyperplasia were upgraded to malignancy, resulting in a final malignancy rate of 19% (n = 29/151). Most malignant lesions were invasive carcinomas (83%, n = 24/29); most invasive carcinomas were of lobular subtype (54%, n = 13/24). Most high-risk lesions were radial scars/complex sclerosing lesions (62%, n = 31/50). Most benign results represented fibrocystic change (66%, n = 49/74). A subset (11%, n = 8/74) of benign results were considered discordant and subsequently excised, with none representing malignancy. CONCLUSION. The final malignancy rate of 19% in architectural distortion without a sonographic correlate justifies a recommendation for biopsy using DBT VAB. CLINICAL IMPACT. Our results highlight the utility of DBT VAB in the era of DBT. The detailed radiologic-pathologic correlations will assist radiologists in assessing concordance when performing DBT VAB for architectural distortions and provide a reference for future patient management.

Flat epithelial atypia: What the radiologist needs to know in 2021

The World Health Organization defines flat epithelial atypia (FEA), as a "presumably neoplastic intraductal alteration characterized by the replacement of native epithelial cells by a single layer or three to five layers of mildly atypical cells.". In this article, we will review FEA and compare its characteristics and differences with other atypical high-risk breast lesions. In addition, the imaging appearance of FEA will be described. Finally, we will discuss current outcomes and provide an update on its management based on the last recommendations.

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.

B3 lesion upgrade rates in a tertiary Australian breast centre: a 8-year experience (2012-2019)

BACKGROUND

B3 breast lesions identified on core needle biopsy have uncertain malignant potential. Traditional management of these lesions has been surgical excision, but there is growing interest in less invasive and more cost-effective alternatives such as vacuum-assisted excisional biopsy (VAEB). Determining the rate of malignant upgrade for B3 lesions is important as it may identify low-risk lesions where VAEB could be considered.

METHODS

A retrospective study was conducted of women undergoing an elective excisional biopsy for a B3 lesion identified on core needle biopsy at a tertiary Australian breast centre. The pre-operative biopsy diagnosis and subsequent excisional biopsy diagnosis were used to calculate the proportion of cases where the diagnosis was upgraded to malignancy.

RESULTS

A total of 299 eligible patients were identified. Pre-operative diagnosis of papillary lesion with atypia was associated with the highest upgrade rate (50%, n = 12). The next highest upgrade rates occurred in those with flat epithelial atypia (37.50%, n = 8); atypical ductal hyperplasia (24.71%, n = 85); lobular carcinoma in situ (LCIS)/atypical lobular hyperplasia with calcification (17.65%, n = 17); and papillary lesion without atypia (4.72%, n = 106). Patients with radial scar (n = 51), classical LCIS without calcification (n = 7) and mucocoele-like lesion (n = 8) had a 0% upgrade rate.

CONCLUSION

VAEB may be appropriate for low malignant risk lesions such as papillary lesion without atypia, mucocoele-like lesion and radial scar lesion without atypia. Open-surgical-excisional biopsy remains appropriate for high upgrade lesions such as atypical ductal hyperplasia, papillary lesion with atypia, flat epithelial atypia and classical LCIS with calcification. Long-term prospective randomized multicentre studies and continuing multidisciplinary approach is recommended for future clinical implementation.