Lobular Neoplasia Research Articles

E-cadherin staining in the diagnosis of lobular versus ductal neoplasms of the breast: the emperor has no clothes.

Categorizing breast neoplasia as ductal or lobular is a daily exercise that relies on a combination of histologic and immunohistochemical tools. The historically robust link between loss of the E-cadherin molecule and lobular neoplasia has rendered staining for E-cadherin by immunohistochemistry a staple of this diagnostic process. Unfortunately, discordances between E-cadherin expression and histomorphology, and variations in E-cadherin staining patterns and intensities abound in clinical practice, but are often neglected in favour of a binary interpretation of the E-cadherin result. In this article, we highlight the complexities of E-cadherin expression through a review of the E-cadherin protein and its associated gene (CDH1), the mechanisms leading to aberrant/absent E-cadherin expression, and the implications of these factors on the reliability of the E-cadherin immunohistochemical stain in the classification of ductal versus lobular mammary neoplasia.

Altered cytokeratin 5 expression in breast lobular myoepithelial cells

AimsCytokeratin 5 (CK5) is a surrogate maker of progenitor cells and early glandular and myoepithelial cells (MECs) in the breast, and CK5 expression in breast MECs varies from ducts to...

Abstract PO3-07-09: B3 breast lesions in Asian Centers: malignant upgrade rates and risk factors

Abstract Background Lesions of uncertain malignant potential in the breast (B3 lesions) are composed of a wide spectrum of pathologies with differing risks of breast cancer. With the widespread implementation of screening programs globally, the incidence of these lesions has increased substantially. Asian women tend to have smaller and denser breasts than Western women, making identifying and treating these lesions more challenging. Previous papers quote an upgrade of B3 lesions to malignancy such as ductal carcinoma in situ (DCIS) or cancer at rates of 9.9% to 35.1%. Malignant upgrade on final histology increases patient anxiety and healthcare costs as a second surgical intervention is often required for pathological clearance or lymph node staging. This study aimed to assess the malignant upgrade rate of B3 lesions in Asian women and to evaluate any key factors that may predict the risk of a malignant upgrade. Materials and Methods A retrospective multicentre international study was done on patients at Seoul National University Hospital (SNUH), South Korea, from April 2021 to 2023, and Tan Tock Seng Hospital (TTSH), Singapore, between March 2006 and 2023. Patients who were diagnosed with a B3 lesion on initial breast core needle biopsy and underwent surgical open excision were included in the study. Results A total of 1049 patients were diagnosed with B3 lesions, with 154 (14.7%) upgrading to malignancy. The most common malignancy was DCIS, 118 (76.6%), followed by invasive ductal carcinoma (IDC), 20 (13.0%) and papillary carcinoma, 4 (2.6%). Within the types of B3 lesions, the malignant upgrade rates were found: atypical ductal hyperplasia (ADH), 88/252 (35%); intraductal papilloma (IDP) with atypia, 16/55 (29%); lobular neoplasia (LN), 9/34 (26%); and radial scar (RS), 5/21 (24%). Most patients had both ultrasound and mammographic evaluation, and all lesions in the study were graded BIRADS 4A and above. Univariate analysis showed that age >50 (OR 2.30 [1.61-3.31], p< 0.001), BMI >23 (OR 2.21 [1.20-4.12], p=0.01), post-menopausal status (OR 2.43 [1.34-4.34], p< 0.001), lesion being identified on mammography (OR 3.00 [2.04-4.51], p< 0.001) and presence of microcalcifications on mammography (OR 0.63 [0.41-0.98], p=0.04) were risk factors for malignant upgrade. Conclusion Based on our analysis of Asian women, post-menopausal patients with microcalcifications on mammography and a B3 biopsy result should be treated with a higher degree of suspicion for underlying malignancy. Surgical excision with adequate margins should be routinely considered for B3 lesions such as ADH, IDP with atypia, LN and RS. Avoidance of surgery or vacuum-assisted removal can be considered for younger patients with only ultrasound findings and diagnosis of FEA and IDP. Table 1. Malignant upgrade after excision Table 2. Clinical characteristics of all patients according to malignant upgrade Table 3. Univariate and multivariate analysis for malignant upgrade Citation Format: Wei Wen Ang, Ji-Jung Jung. B3 breast lesions in Asian Centers: malignant upgrade rates and risk factors [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-07-09.

Abstract NG02: Distinct genomic and immunologic tumor evolution in germline TP53-driven breast cancers

Abstract NG02: Distinct genomic and immunologic tumor evolution in germline TP53-driven breast cancers

Upgrade Rate and Long-term Outcomes of Lobular Neoplasia

Upgrade Rate and Long-term Outcomes of Lobular Neoplasia

Upgrade Rates and Breast Cancer Development Among Germline Pathogenic Variant Carriers with High-Risk Breast Lesions.

High-risk lesions (HRL) of the breast are risk factors for future breast cancer development and may be associated with a concurrent underlying malignancy when identified on needle biopsy; however, there are few data evaluating HRLs in carriers of germline pathogenic variants (PVs) in breast cancer predisposition genes. We identified patients from two institutions with germline PVs in high- and moderate-penetrance breast cancer predisposition genes and an HRL in an intact breast, including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), and lobular neoplasia (LN). We calculated upgrade rates at surgical excision and used Kaplan-Meier methods to characterize 3-year breast cancer risk in patients without upgrade. Of 117 lesions in 105 patients, 65 (55.6%) were ADH, 48 (41.0%) were LN, and 4 (3.4%) were FEA. Most PVs (83.8%) were in the BRCA1/2, CHEK2 and ATM genes. ADH and FEA were excised in most cases (87.1%), with upgrade rates of 11.8% (95% confidence interval [CI] 5.5-23.4%) and 0%, respectively. LN was selectively excised (53.8%); upgrade rate in the excision group was 4.8% (95% CI 0.8-22.7%), and with 20 months of median follow-up, no same-site cancers developed in the observation group. Among those not upgraded, the 3-year risk of breast cancer development was 13.1% (95% CI 6.3-26.3%), mostly estrogen receptor-positive (ER +) disease (89.5%). Upgrade rates for HRLs in patients with PVs in breast cancer predisposition genes appear similar to non-carriers. HRLs may be associated with increased short-term ER+ breast cancer risk in PV carriers, warranting strong consideration of surgical or chemoprevention therapies in this population.

ASO Visual Abstract: Lobular Neoplasia Diagnosed by MRI-Guided Breast Biopsy-Identifying Upgrade Rate to Malignancy and Outcomes of Clinical and Surgical Management.

ASO Visual Abstract: Lobular Neoplasia Diagnosed by MRI-Guided Breast Biopsy-Identifying Upgrade Rate to Malignancy and Outcomes of Clinical and Surgical Management.

Lobular Neoplasia Diagnosed by MRI-Guided Breast Biopsy: Identifying Upgrade Rate to Malignancy and Outcomes of Clinical and Surgical Management.

The aim of this study was to determine surgical and clinical outcomes of lobular neoplasia (LN) diagnosed by magnetic resonance imaging (MRI) biopsy, including upgrade to malignancy, and to assess for characteristics associated with upgrade. A single-institution retrospective study, between 2013 and 2022, of patients with histopathological findings of LN via MRI-guided biopsy was performed using an institutional database and review of the electronic medical records. Decision for excision or surveillance was made by a multidisciplinary team per institutional practice. Patient demographics and imaging characteristics were summarized using descriptive analyses. Upgrade was defined as upgrade to cancer on surgical pathology for patients treated with excision or the development of cancer at the biopsy site during surveillance. The Wilcoxon rank-sum test and Fisher's exact test were used to compare features of the upgraded cohort with the remainder of the group. Ninety-four MRI biopsies diagnosing LN were included. Median age was 57 years (range 37-78years). Forty-six lesions underwent excision while 48 lesions were surveilled. The upgrade rate was 7.4% (7/94). Upgrades in the excised cohort consisted of pleomorphic lobular carcinoma in situ (LCIS; n=1), ductal carcinoma in situ (DCIS; n=3) and invasive lobular carcinoma (ILC; n=2), while one interval development of DCIS was observed at the site of biopsy in the surveillance cohort. No MRI or patient variables were associated with upgrade. In this contemporary cohort of MRI-detected LNs, the upgrade rate was low. Omission of surgery for MRI-detected LNs in carefully selected patients may be considered in a shared decision-making capacity between the patient and the treatment team. Larger cohorts are needed to determine factors predictive of upgrade risk.

Spectrum of histopathologic findings in risk-reducing bilateral prophylactic mastectomy in patients with and without BRCA mutations

Many germline mutations have been implicated in breast cancer pathogenesis and despite several studies on occult atypical lesions in prophylactic mastectomy specimens from patients with BRCA1/2 mutations, there are very limited data on other genes associated with increased breast cancer risk and the distribution of lesions in patients with hereditary breast cancer. We identified 207 patients who underwent bilateral prophylactic mastectomy due to germline mutations in BRCA1/2, PALB2, CHEK2, ATM, CDH1, PTEN, BARD1, or strong family history between 2015 and 2023. Patients with biopsy-proven past or current invasive breast carcinoma or carcinoma in-situ preoperatively were excluded. In addition to multiple benign lesions, the following atypical lesions were identified: flat epithelial atypia (16.9%), atypical ductal hyperplasia (14.0%), lobular neoplasia (14.0%), ductal carcinoma in-situ (4.3%), invasive ductal carcinoma (0.4%). Both low-grade and high-grade pathway lesions were identified in this cohort, and in a subset of patients, they co-occurred. The frequency of atypical lesions identified in patients with strong family history were comparable to those with proven germline mutation. PTEN immunohistochemistry showed loss of expression in ductal carcinoma in-situ and tubular adenomas in PTEN-mutant patients. Overall, findings from this cohort support the benefit of prophylactic mastectomy in patients with germline mutations and/or strong family history. Additionally, this is the first demonstration that PTEN immunohistochemistry may be helpful in identifying germline mutations in patients with atypical or neoplastic proliferations.

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

BackgroundManagement 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). MethodsWe 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. Results719 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. ConclusionsCD was associated with increased UR. ADH/LN had the highest UR.

Contrast-Enhanced Mammography (CEM) compared to Breast Magnetic Resonance (MRI) in the evaluation of breast lobular neoplasia.

To compare the diagnostic performance (detection, assessment of correct disease extent and multifocality/centricity) of Contrast-Enhanced Mammography (CEM) Versus Breast Magnetic Resonance (MRI) in the study of lobular neoplasms. We retrospectively selected all the patients who underwent surgery for a lobular breast neoplasm, either an in situ or an invasive tumor, and had undergone both breast CEM and MRI examinations during the pre-surgical planning. Wilcoxon Signed Rank test was performed to assess the differences between size measurements using the different methods and the post-surgical pathological measurements, considered the gold standard. The agreement in identifying multifocality/multicentricity among the different methods and the pathology was assessed using the Kappa statistics. We selected 19 patients, of which one presented a bilateral neoplasm. Then, the images of these 19 patients were analyzed, for a total of 52 malignant breast lesions. We found no significant differences between the post-surgical pathological size of the lesions and the calculated size with CEM and MRI (p-value of the difference respectively 0.71 and 0.47). In all 20 cases, neoplasm detection was possible both with CEM and MRI. CEM and MRI showed an excellent ability to identify multifocal and multicentric cases (K statistic equal to 0.93 for both the procedures), while K statistic was 0.11 and 0.59 for FFDM and US, respectively. The findings of this study suggest that CEM is a reliable imaging technique in the preoperative setting of patients with lobular neoplasm, with comparable results to breast MRI.

Evaluating the use of vacuum-assisted excisions in the management of B3 breast lesions.

To evaluate the use of vacuum-assisted excisions (VAEs) in the management of B3 lesions within a single UK breast care centre. Assessment was made by determining the upgrade rates of the different B3 lesions at VAE. The study population comprised all patients who had a B3 result and subsequently underwent a VAE between November 2016 and October 2021. Patients with ipsilateral cancers were excluded. Retrospective biopsy and VAE results were reviewed. Upgrade rates and confidence intervals were calculated, and statistical significance was tested to determine any differences between upgrade rates of the B3 groups. 480 VAEs for B3 lesions were performed, with 10 excluded. Overall upgrade rate was 5%. 87.5% of upgrades were to non-invasive disease. Atypical intraductal epithelial proliferation (AIDEP) had a 15% upgrade rate, significantly different to lobular neoplasia (2%), papilloma without atypia (0%), and radial scar without atypia (0%). 10% of B3 lesions with atypia were upgraded, significantly different to 0% of B3 lesions without atypia. B3 lesions diagnosed by vacuum-assisted biopsy (VAB) had a significantly higher upgrade rate of 8% compared with 2% for lesions diagnosed by core biopsy (CBX), although this result was impacted by high numbers of AIDEP diagnosed by VAB. The results suggest using VAE for the management of AIDEP is appropriate. However, they also indicate that by performing VAEs of papillomas and radial scars without atypia, overtreatment may be occurring. This study adds to the ongoing discussion on the best treatment of B3 breast lesions.

Update on Lobular Neoplasia.

Lobular neoplasia (LN) is a histopathologic entity that encompasses both lobular carcinoma in situ (LCIS) and atypical lobular hyperplasia (ALH). Management of LN is known to be variable and institutionally dependent. The variability in approach after a diagnosis of LN at percutaneous breast biopsy derives in part from heterogeneity in the literature, resulting in a range of reported upgrade rates to malignancy after initial identification at percutaneous biopsy, and also from historical shifts in understanding of the natural history of LN. It has become increasingly recognized that not all LN is the same and that distinct variants of LN such as pleomorphic LCIS and florid LCIS have distinct natural histories and distinct likelihoods of upgrade to malignancy. In addition, it is also increasingly understood that appropriate management of LN relies on scrupulous radiologic-pathologic correlation. This review details the imaging features and histopathologic nature of ALH, classic-type LCIS, and the LCIS variants; addresses changes in the historical understanding of this entity contributing to confusion regarding its management; and discusses the importance of performing radiologic-pathologic correlation after percutaneous biopsy to help guide appropriate management steps when LN is encountered. In addition to the short-term implications of an LN diagnosis in terms of upgrade and surgical outcomes, the long-term implications of an LN diagnosis regarding risk of developing a later breast cancer are examined. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Management of screening-detected lobular neoplasia in the era of digital breast tomosynthesis: A preliminary study

PurposeThe purpose of this study is to determine upgrade rates of lobular neoplasia detected by screening digital breast tomosynthesis (DBT) and to determine imaging and clinicopathological features that may influence risk of upgrade. MethodsMedical records were reviewed of consecutive women who presented with screening DBT-detected atypical lobular hyperplasia (ALH) and/or lobular carcinoma in situ (LCIS) from January 1, 2013, to June 30, 2020. Included patients underwent needle biopsy and had surgery or at least two-year imaging follow-up. Imaging and clinicopathological features were compared between upgraded and nonupgraded cases of lobular neoplasia using the Pearson's chi-squared test and the Wilcoxon signed-rank test. ResultsDuring the study period, 107 women (mean age 55 years, range 40–88 years) with 110 cases of ALH and/or LCIS underwent surgery (80.9%, n = 89) or at least two-year imaging follow-up (19.1%, n = 21). The overall upgrade rate to cancer was 5.5% (6/110), and the upgrade rate to invasive cancer was 3.6% (4/110). The upgrade rate of ALH to cancer was 4.1% (3/74), whereas the upgrade rate of LCIS to cancer was 9.4% (3/32) (p = .28). The upgrade rate of cases presenting as calcifications was 4.2% (3/71), whereas the upgrade rates of cases presenting as noncalcified findings was 7.7% (3/39) (p = .44). ConclusionsThe upgrade rate of screening DBT-detected lobular neoplasia is less than 6%. Surveillance rather than surgery can be considered for lobular neoplasia, particularly in patients with ALH and in those with screening-detected calcifications leading to the diagnosis.

In Search of Calcifications : Histologic Analysis and Diagnostic Yield of Stereotactic Core Needle Breast Biopsies.

Stereotactic core needle biopsy (SCNB) is used in the diagnostic assessment of suspicious mammographic calcifications to rule out breast ductal carcinoma in situ (DCIS). With advances in imaging technology and increased biopsy tissue volume, the detection rate of calcifications and DCIS in SCNB is unclear. This retrospective study included 916 consecutive SCNBs for calcifications performed on 893 patients in a 2-year period. We found the cancer detection rate was 27.1% (DCIS, 23.7%; invasive, 3.4%). The detection rate for calcifications was 74.8% with the standard 3 levels. Additional leveling of calcification-negative cases further increased the detection of both calcifications (to 99.4% of cases) and DCIS (to 32.9% of cases). Lobular neoplasia (LN) was diagnosed in 41 cases. Twenty-five (61.0%) cases of LN were incidental without associated calcification. Of 32 invasive carcinomas detected on SCNB, 87.5% were T1a or less, and calcifications were associated with atypical ductal hyperplasia/DCIS or LCIS. The common benign lesions associated with calcifications were fibrocystic change (32.5%), fibroadenomatous change (30.2%), and columnar cell change and hyperplasia (8.2%). We determined the up-to-date detection rates of calcification and DCIS in SCNB, as well as the common benign and malignant breast lesions associated with calcifications. Additional levels significantly increase the detection rate when standard levels show only stromal or scant/absent calcifications. Lobular neoplasia is often an incidental finding in SCNB for calcifications. When calcifications are present with LN, they are commonly florid, pleomorphic LCIS, or with concurrent invasive carcinoma.

De-escalation of Surgical Intervention and Contemporary Management Recommendations for Lobular Neoplasia, Atypical Ductal Hyperplasia, and Ductal Carcinoma In Situ

De-escalation of Surgical Intervention and Contemporary Management Recommendations for Lobular Neoplasia, Atypical Ductal Hyperplasia, and Ductal Carcinoma In Situ

Management of Lobular Neoplasia Diagnosed by Core Biopsy.

Lobular neoplasia (LN) involves proliferative changes within the breast lobules. LN is divided into lobular carcinoma in situ (LCIS) and atypical lobular hyperplasia (ALH). LCIS can be further subdivided into three subtypes: classic LCIS, pleomorphic LCIS, and LCIS with necrosis (florid type). Because classic LCIS is now considered as a benign etiology, current guidelines recommend close follow-up with imaging versus surgical excision. The goal of our study was to determine if the diagnosis of classic LN on core needle biopsy (CNB) merits surgical excision. This is a retrospective, observational study conducted at Mount Auburn Hospital, Cambridge, MA, from May 17, 2017, through June 30, 2020. We reviewed the data of breast biopsies conducted at our hospital over this period and included patients who were diagnosed with classic LN (LCIS and/or ALH) and excluded patients having any other atypical lesions on CNB. All known cancer patients were excluded. Of the 2707 CNBs performed during the study period, we identified 68 women who were diagnosed with ALH or LCIS on CNB. CNB was performed for an abnormal mammogram in the majority of patients (60; 88%) while 7(10.3%) had an abnormal breast magnetic resonance imaging study (MRI), and 1 had an abnormal ultrasound (US). A total of 58 patients (85%) underwent excisional biopsy, of which 3 (5.2%) showed malignancy, including 2 cases of DCIS and 1 invasive carcinoma. In addition, there was 1 case (1.7%) with pleomorphic LCIS and 11 cases with ADH (15.5%). The management of LN found on core biopsy is evolving, with some advocating surgical excision and others recommending observation. Our data show a change in diagnosis with excisional biopsy in 13 (22.4%) of patients with 2 cases of DCIS, 1 invasive carcinoma, 1 pleomorphic LCIS, and 9 cases of ADH, diagnosed on excisional biopsy. While ALH and classic LCIS are considered benign, the choice of ongoing surveillance versus excisional biopsy should be made with shared decision making with the patient, with consideration of personal and family history, as well as patient preferences.

Radiological Features of B3 Lesions in Mutation Carrier Patients: A Single-Center Retrospective Analysis

Background. To evaluate the radiological features of B3 lesions in patients with genetic mutations to establish an anatomo-radiological correlation. Methods. A total of 227 women with a histological diagnosis of B3 breast lesion were enrolled. Breast images of 21 patients with genetic test positivity for mutations in genes associated with breast cancer were analyzed. Results. BRCA1 was the most frequent mutation (n = 12) followed by ATM (n = 6) and BRCA2 (n = 3). The histological findings showed nine atypical ductal hyperplasia (ADH), six lobular neoplasia (LN) including lobular carcinoma in situ (LCIS), three flat epithelial atypia (FEA) and three radial scar (RS) lesions. The results showed a significance difference between B3 lesion distribution in the three subgroups of mutations. LN and FEA showed the highest malignancy correlation. Patient age and risk anamnesis were factors that significantly influenced the malignancy rate. By mammography, 90.5% of lesions appeared as microcalcifications. By ultrasound, 13 lesions were observed as hypoechoic lesions. On breast MRI, 16 lesions were detected as a mass enhancement in all groups. DWI and kinetic curves significantly correlated with the risk of cancer. Conclusions. The radiological features of B3 lesions may help in the diagnosis of breast cancer malignancy. The high malignancy rate of cancer in our sample suggests they should always be surgically excised.

The Upgrade Risk of B3 Lesions to (Pre)Invasive Breast Cancer After Diagnosis on Core Needle or Vacuum Assisted Biopsy. A Belgian National Cohort Study

IntroductionFlat epithelial atypia (FEA), lobular neoplasia (LN), papillary lesions (PL), radial scar (RS) and atypical ductal hyperplasia (ADH) are lesions of uncertain malignant potential and classified as B3 lesions by the European guidelines for quality assurance in breast cancer screening and diagnosis. Current management is usually wide local excision (WE), surveillance may be sufficient for some. We investigated the upgrade rate of B3 lesions to breast malignancy in a subsequent resection specimen after diagnosis on core needle–or vacuum assisted biopsy (CNB–VAB) in a national population-based series. MethodsUsing data from the Belgian Cancer Registry (BCR) between January 1, 2013 and December 31, 2016, inclusion criteria were new diagnosis of a B3 lesion on CNB or VAB with subsequent histological assessment on a wider excision specimen. Histological agreement between first- and follow-up investigation was analyzed to determine the upgrade risk to ductal adenocarcinoma in situ (DCIS) or invasive breast cancer (IC) according to the type of B3 lesion. ResultsOf 1855 diagnosed B3 lesions, 812 were included in this study: 551 after CNB–261 after VAB. After diagnosis on CNB and VAB, we found 19.0% and 14.9% upgrade to malignancy respectively. Upgrade risks after CNB and VAB were: FEA 39.5% and 17.6%; LN 40.5% and 4.3%; PL 10.4% and 12.5%; RS 25.7%and 0.0%; ADH 29.5% and 20.0%. ConclusionBased on the observed upgrade rate we propose three recommendations: first, resection of ADH, and FEA with WE; second, resection of RS and classical LN with therapeutic VAB and further surveillance when radio-pathological correlation is concordant; third, surveillance of PL.

High-Risk Breast Lesions Diagnosed by Ultrasound-Guided Vacuum-Assisted Excision.

The aim of this study was to analyze the role of ultrasound-guided vacuum-assisted excision (US-guided VAE) in the treatment of high-risk breast lesions and to evaluate the clinical and US features of the patients associated with recurrence or development of malignancy. Between April 2010 and September 2021, 73 lesions of 73 patients underwent US-guided VAE and were diagnosed with high-risk breast lesions. The incidence of recurrence or development of malignancy for high-risk breast lesions was evaluated at follow-up period. The clinical and US features of the patients were analyzed to identify the factors affecting the recurrence or development of malignancy rate. Only benign phyllodes tumors on US-guided VAE showed recurrences, while other high-risk breast lesions that were atypical ductal hyperplasia (ADH), lobular neoplasia (atypical lobular hyperplasia/lobular carcinoma in situ), radial scar, and flat epithelial atypia did not show recurrences or malignant transformation. The recurrence rate of the benign phyllodes tumor was 20.8% (5/24) in a mean follow-up period of 34.3months. The recurrence rate of benign phyllodes tumor with distance from nipple of less than 1cm was significantly higher than that of lesions with distance from nipple of more than 1cm (75% vs. 10%, p < 0.05). Benign phyllodes tumors without concurrent breast cancer could be safely followed up instead of surgical excision after US-guided VAE when the lesions were classified as BI-RADS 3 or 4A by US.