What is the significance of flat epithelial atypia and what are the management implications?

Distance of Biopsy-Confirmed High-Risk Breast Lesion from Concurrently Identified Breast Malignancy Associated with Risk of Carcinoma at the High-Risk Lesion Site

High-risk breast lesions including incidental intraductal papilloma without atypia (IPA), lobular hyperplasia (LCIS or ALH), flat epithelial atypia (FEA) and complex sclerosing lesion (CSL) are not routinely excised due to low upgrade rates to carcinoma. We aim to identify features of these lesions predictive of upgrade when identified concurrently with invasive disease. Methods: A single-center retrospective cohort study was performed for patients who underwent multi-site lumpectomies with invasive disease at one site and a high-risk lesion at another site between 2006 and 2021. A multinomial logistic regression was performed. Results: Sixty-five patients met the inclusion criteria. Four patients (6.2%) had an upgrade to in situ disease (DCIS) and one (1.5%) to invasive carcinoma. Three upgraded high-risk lesions were ipsilateral to the concurrent carcinoma and two were contralateral. In the multivariate model, a high-risk lesion within 5 cm of an ipsilateral malignancy was associated with increased risk of upgrade. The 3.8% upgrade rate for high-risk lesions located greater than 5 cm from ipsilateral malignancy or in the contralateral breast suggests that omission of excisional biopsy may be considered. Excisional biopsy of lesions within 5 cm of ipsilateral malignancy is recommended given the 25% upgrade risk in our series.

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 impact of vacuum-assisted excision in the management of indeterminate B3 lesions in the NHS Breast Screening Programme in England

AIM

To assess the impact of vacuum-assisted excision (VAE) on the management of B3 lesions in the England NHS Breast Screening Programme following an update of national guidance. A secondary aim was to investigate the histological features of malignancies resulting from upgrade of B3 lesions by either VAE or surgery.

MATERIALS AND METHODS

The study population was all women recalled for assessment after breast screening who had a wide-bore needle biopsy with a B3 result over the period 01/04/2018 to 31/03/2019. Data were extracted from the National Breast Screening Service (NBSS) computer system at unit level. Women with a B3 result were split into those with and without atypia. The upgrade rates and histological features of malignancies in the different groups were analysed.

RESULTS

In total, 2,234,514 women attended for screening between 1/4/218 and 31/3/2019, 84,559 women were referred to assessment, and of those 40,037 women had a core biopsy resulting in 3,355 were B3 lesions (8.38%). Within these, 556 cancers were diagnosed, giving an upgrade rate of 16.57% (556/3,355). The upgrade for B3 lesions with atypia was significantly higher than for B3 lesions without atypia (29.1% versus 13.3%, p<0.001).

CONCLUSION

The introduction of the new B3 guidelines has resulted in 73.8% of B3 lesions with atypia and 65.1% of B3 lesions with no atypia having VAE rather than surgery. The data highlights the importance of managing these indeterminate lesions appropriately with an overall upgrade rate of 16.57%.

Role of vacuum assisted excision in minimising overtreatment of ductal atypias

PURPOSE

B3 lesions are indeterminate lesions of uncertain malignant potential. They include lesions with and without epithelial atypia. Those with atypia include atypical intraductal epithelial proliferation (AIDEP)/atypical ductal hyperplasia (ADH) and flat epithelial atypia (FEA). They are traditionally managed with surgery. Vacuum assisted excision (VAE) allows larger samples to be obtained using a vacuum assisted biopsy (VAB) device, which equates to a surgical biopsy. We propose that VAE and mammographic surveillance is a safe alternative to surgery in managing the ductal atypias; (AIDEP/ADH and FEA).

METHOD

Retrospective analysis of prospectively collected data on B3 lesions (April 2009 - March 2016) from consecutive breast screening patients diagnosed with AIDEP/ADH or FEA on initial diagnostic core biopsy. Mammographic abnormality, breast density, size, management pathway and upgrade to cancer and types of cancer were also collected during the treatment pathway and 5 year surveillance period (April 2009 - April 2019).

RESULTS

273 cases of ductal atypia were identified. 187/273 (68.5 %) cases were managed with VAE only as no upgrade to malignancy and then 5 year mammographic surveillance. 34/273 (12.5 %) cases had a VAE diagnosing malignancy. 24/273 (8.8 %) cases had a VAE and then a surgical biopsy due to radiological or pathological concern, 8/24 upgraded to malignancy. 22/273 (8%) cases had a surgical diagnostic biopsy, 9/22 (41 %) cases were upgraded to malignancy. In total 51/273 (19 %) cases were diagnosed with cancer on the new pathway (13 invasive (all ER positive and Her2 negative) and 38 non-invasive, (34 ductal carcinoma in situ (DCIS) and 4 cases of lobular carcinoma in situ (LCIS)). While 17/273 (6.2 %) cases developed malignancy (12 invasive (all HER2 negative) and 4 DCIS and 1 LCIS) during the 5 year surveillance period.

CONCLUSIONS

VAE is a safe alternative to surgery in managing ductal atypias. 187/273 (68.5 %) women avoided surgery. While 34/51 cancers (66.7 %) were diagnosed preoperatively using VAE, allowing the women to have a single therapeutic procedure.

[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.

Positive predictive value for malignancy of pure flat epithelial atypia diagnosis by percutaneous needle biopsy of the breast: management of FEA in ultrasonography

BACKGROUND

Some reports suggest that the rate of definitive diagnosis of malignant tumors, namely, the final diagnosis being revised to a higher stage, in patients diagnosed as having flat epithelial atypia (FEA) by percutaneous needle biopsy of the breast (PNB) is as low as 0-3 %. However, other reports suggest that the rate is as high as 10 % or more, bringing confusion on this issue. We examined the positive predictive value for malignancy in the patients diagnosed as having pure FEA and the patients' radiolopathological characteristics observed in our hospital.

METHODS

Of the patients who underwent PNB in our facility, those who were diagnosed as having pure FEA were recruited as the subjects of this study.

RESULTS

Of the 4,197 consecutive patients who underwent PNB, 44 (1.0 %) were diagnosed as having pure FEA following a re-examination. Among 44 cases, 39 cases were selected as the subjects of this study. Among the 39 patients, six patients were diagnosed as having malignant lesions, two of whom had invasive carcinoma of no special type (papillotubular type), one had tubular carcinoma, one had ductal carcinoma in situ (DCIS) of high nuclear grade, one had DCIS of intermediate nuclear grade, and one had DCIS of low nuclear grade. The diameters of 6 malignant lesions were 10-30 mm at ultrasonography (US) examination. Five of the 39 patients had contralateral breast cancer.

CONCLUSION

The positive predictive value for malignancy of pure FEA was 15.7 %. The patients with pure FEA may make a follow up without an excisional biopsy when the lesion sizes less than 10 mm on US examination.

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.

Pure flat epithelial atypia is uncommon in subsequent breast excisions for atypical epithelial proliferation

The management of atypical intraductal lesions of the breast remains controversial. In the present study, the subsequent surgical excision results and follow-up data on 86 (3.65%) atypical intraductal lesions and 78 (3.31%) low-grade ductal carcinoma in situ (DCIS) from a cohort of 2358 needle biopsies were examined. There were 17 cases (0.72%) of pure flat epithelial atypia (FEA), 44 (1.87%) pure atypical ductal hyperplasia (ADH), three (0.13%) pure atypical lobular hyperplasia (ALH), 18 (0.76%) combined ADH + FEA, three (0.13%) combined ALH + FEA and one (0.04%) combined ALH + FEA + ADH. Subsequent surgical excisions were done in 53 cases and revealed the following incidences of malignancy: pure FEA (1/8); pure ADH (17/31); FEA + ADH (7/10); FEA + ALH (2/3); and FEA + ALH + ADH (0/1), with pure FEA showing significantly lower incidence of malignancy. In this cohort, there were 703 carcinomas including 155 DCIS with 78 cases (50.3%) being low-grade. FEA with ADH (and/or ALH) was present in 22 (28.2%) of these 78 cases of low-grade DCISs at surgical excisions. Pure FEA was not detected in any of the subsequently excised surgical materials of the atypical intraductal lesions nor the low-grade DCISs. Thus, pure FEA was very unusual in surgical specimens. When pure FEA is detected at needle biopsy, a wait and see approach can be adopted. However, when the FEA is associated with other concomitant atypical intraductal lesions, especially ADH, further excision should be contemplated.