Atypia Involving Fibroadenomas: Outcomes and Upgrade Rates.

OBJECTIVE: Fibroadenomas (FAs) involved by atypia are rare. Consensus guidelines for management of FAs involved by atypia when diagnosed on image-guided biopsy do not exist because of limited data reporting surgical upgrade rates to ductal carcinoma in situ (DCIS) or invasive malignancy. Therefore, these lesions commonly undergo surgical excision. METHODS: This single-institution retrospective study identified cases of FAs involved by atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and/or lobular carcinoma in situ (LCIS) diagnosed on image-guided biopsy between January 2014 and April 2023 to determine upgrade rates. Cases with incidental atypia adjacent to but not involving FAs were excluded. RESULTS: Among 1736 FAs diagnosed on image-guided biopsy, 32 cases (1.8%) were FAs involved by atypia including 43.8% (14/32) ALH, 28.1% (9/32) ADH, 18.8% (6/32) LCIS, 6.3% (2/32) LCIS + ALH, and 3.1% (1/32) unspecified atypia. The most common imaging finding was a mass. Most cases, 81.3% (26/32), underwent subsequent surgical excisional biopsy. A single case of ADH involving and adjacent to an FA was upgraded to FA involved by low-grade DCIS on excision for an overall surgical upgrade rate of 3.8%. There were no cases upgraded to invasive malignancy. For those omitting surgical excision, there was no subsequent malignancy diagnosis at the FA biopsy site over a mean follow-up of 73 months. CONCLUSION: Cases of radiologic-pathologic concordant FAs involved by atypia have a low upgrade rate of 3.8% and should undergo multidisciplinary review. Larger multi-institutional analysis is needed to determine whether guidelines for excision of atypia should apply to atypia involving FAs.

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

OBJECTIVE: 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. METHOD: 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. RESULTS: Ninety-four MRI biopsies diagnosing LN were included. Median age was 57 years (range 37-78 years). 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. CONCLUSIONS: 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.

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

PURPOSE: The 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. METHODS: Medical 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. RESULTS: During 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). CONCLUSIONS: The 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.

Invasive Lobular Carcinoma Mimicking Encapsulated Papillary Carcinoma with a Literature Review: A Rare Variant Detected Serendipitously.

Invasive lobular carcinoma with papillary features is a newly proposed variant which presents as a relatively well-circumscribed mass lesion with at least partial peripheral thickened fibrous capsule and central delicate fibrovascular cores, morphologically mimicking encapsulated papillary carcinoma or solid papillary carcinoma. There are only 5 cases described in literature. We here report an interesting example of invasive lobular carcinoma with papillary growth pattern surrounded by a thick fibrous capsule, mimicking encapsulated papillary carcinoma (EPC). The lobular nature of the tumor was confirmed by the absence of membranous expression of E-cadherin and p120 catenin. The lobular cytological features are subtle in this variant and may be overlooked. Differentiation of this variant from papillary carcinomas is crucial for correct tumor categorization, staging and most importantly, proper treatment.

Factors Indicating Surgical Excision in Classical Type of Lobular Neoplasia of the Breast.

Purpose: Classical type of lobular neoplasia (LN) encompassing both atypical lobular hyperplasia and classical lobular carcinoma in situ of the breast is a lesion with uncertain malignant potential and has been the topic of several studies with conflicting outcome results. The aim of our study was to clarify outcome-relevant factors and treatment options of classical LN. Methods: We performed a pathological re-evaluation of the preoperative biopsy specimens and a retrospective clinical and radiological data analysis of 160 patients with LN from the Breast Center Zurich. Open surgery was performed in 65 patients, vacuum-assisted biopsy (VAB) in 79 patients, and surveillance after breast core needle biopsy (CNB) in 16 patients. Results: The upgrade rate into ductal carcinoma in situ/invasive cancer was the highest in case of imaging/histology discordance (40%). If the number of foci in the biopsy specimen was ≥3, the upgrade rate in the consecutive surgical specimens was increased (p = 0.01). The association of classical LN with histological microcalcification correlated with shortened disease-free survival (p < 0.01), whereas other factors showed no impact on follow-up. Conclusions: Surveillance or subsequent VAB after CNB of LN is sufficient in most cases. Careful consideration of individual radiological and histological factors is required to identify patients with a high risk of upgrade into malignancy. In those cases, surgical excision is indicated.

Risk-Associated Lesions of the Breast in Core Needle Biopsies: Current Approaches to Radiological-Pathological Correlation.

Image-guided core needle biopsies (CNBs) of the breast frequently result in a diagnosis of a benign or atypical lesion associated with breast cancer risk. The subsequent clinical management of these patients is variable, reflecting a lack of consensus on criteria for selecting patients for clinical and radiological follow-up versus immediate surgical excision. In this review, the evidence from prospective studies of breast CNB with radiological-pathological correlation is evaluated and summarized. The data support an emerging consensus on the importance of radiologic-pathologic correlation in standardizing the selection of patients for active surveillance versus surgery.

Upgrade Rates of Pure, Radiology-Pathology Concordant Lobular Neoplasia Diagnosed on Breast Core Needle Biopsy: Is Surgical Excision Warranted?

OBJECTIVE: To determine upgrade rates of lobular neoplasia (LN) to malignancy and evaluate factors that may predict upgrade. METHODS: From 5/1/2003 to 12/30/2015, breast lesions diagnosed as LN (atypical lobular hyperplasia [ALH] or classic lobular carcinoma in-situ [LCIS]) on core biopsy that underwent surgical excision or at least 2 years imaging follow-up were identified. A subspecialty trained breast radiologist and pathologist reviewed imaging and pathology slides to confirm diagnosis and to determine if LN represented the target lesion, part of the target lesion, or an incidental finding. Imaging features, original BI-RADS final assessment category, biopsy method, biopsy device and final pathologic diagnosis were documented. Cases with both ALH and LCIS were classified as LCIS for analysis. Reason for biopsy of BI-RADS 2-3 was patient or referring physician preference. Upgrade rates to malignancy were determined for all cases. RESULTS: In this study 73.7% (115/156) lesions were ALH and 26.3% (41/156) were LCIS+/-ALH. Surgical excision and imaging follow-up were performed in 71.2% (111/156) and 28.8% (45/156), respectively. Upgrade rates for ALH and LCIS were 0.0% (0/115) and 7.3% (3/41), respectively. Cancer developed at a site separate from core biopsy in 1.7% (2/115) ALH and 7.3% (3/41) LCIS cases. We found no association of upgrade rate with biopsy type, BI-RADS or target/part of target lesion versus incidental. CONCLUSION: Our study supports consideration of excision for LCIS, given 7.3% upgrade rate. Conversely, imaging surveillance might be appropriate following diagnosis of ALH alone.

[Updated WHO classification of tumors of the breast: the most important changes]. / Aktualisierte WHO-Klassifikation der Tumoren der Mamma: Die wichtigsten Änderungen.

The development of the WHO classification of tumors of the breast is driven by new knowledge from research whose translation into daily practice is considered clinically relevant. The fifth edition represents an update of the fourth edition and essentially follows the previously known systematics. The histologic features of the lesions continue to form the basis of the classification in the update. This also applies to the definition of invasive tumor types. However, several new molecular classifications as well as additional prognostic and predictive factors are presented and discussed, which improve prognosis estimation and therapy decisions. This paper aims to present the main changes in the current WHO classification. These include the revised definition of mixed invasive carcinomas, the introduction of new special invasive entities (tall cell carcinoma with reversed polarity, mucinous cystadenocarcinoma), the deletion of special invasive types and their classification as variants of invasive carcinoma, NST (no special type, including medullary, lipid-rich, glycogen-rich, among others), the typing of primary neuroendocrine neoplasms of the breast by analogy with other organ systems, changes in the dignity criteria of phyllodes tumors, and the revised subtyping of lobular carcinoma in situ (LCIS). In addition to improvements in the fifth edition of the classification, flaws are also highlighted. A section is devoted to new molecular parameters.

Management of Lobular Neoplasia Found on Core Needle Biopsy Performed for Calcifications Using Precise Radiologic-Pathologic Correlation.

OBJECTIVE. The purpose of our study was to evaluate the upgrade rate of calcified lobular neoplasia (LN) versus incidental noncalcified classic LN found on core needle biopsy performed for the evaluation of suspicious calcifications. MATERIALS AND METHODS. This retrospective study included 390 consecutive image-guided breast core needle biopsies with microcalcifications as the target that were performed between December 2009 and July 2017. In 81 of the 390 core biopsies, the highest-risk lesion was LN that then underwent either excision or imaging follow-up. Core biopsy results were compared with excision and imaging follow-up findings. An upgrade of LN was defined as ductal carcinoma in situ or invasive ductal or lobular carcinoma. RESULTS. Of 81 LN diagnosed on core biopsy performed for calcifications, 16 had calcifications within the LN. Fifteen of these 16 cases underwent surgical excision, and three (3/15, 20.0%) were upgraded on excision. Of the 64 core biopsies showing incidental noncalcified LN with benign concordant entities containing calcifications, 42 underwent surgical excision, and one LN (1/42, 2.4%) was upgraded. Twenty-three total lesions (one calcified LN and 22 noncalcified LN) were followed with imaging rather than excision. No cancers were detected among the follow-up group. One case was deemed to have discordant findings on radiologic-pathologic review and was sent for excision, which showed invasive cancer with tubulolobular and lobular features. CONCLUSION. Women undergoing stereotactic core needle biopsy for calcifications revealing noncalcified incidental classic LN and a benign concordant entity that could explain the presence of the target calcifications have a low risk of upgrade and may be followed with imaging. Surgical excision should be offered to women who have LN with calcifications.

Lobular neoplasia detected at MRI-guided biopsy: imaging findings and outcomes.

OBJECTIVE: To review MRI findings of pure lobular neoplasia (LN) on MRI guided biopsy, evaluate surgical and clinical outcomes, and assess imaging findings predictive of upgrade to malignancy. METHODS: HIPAA compliant, IRB-approved retrospective review of our MRI-guided breast biopsy database from October 2008-January 2015. Biopsies yielding atypical lobular hyperplasia or lobular carcinoma in situ were included in the analysis; all biopsy slides were reviewed by a dedicated breast pathologist. Imaging indications, MRI findings, and histopathology were reviewed. Statistical analysis was performed using the two-tailed Fisher exact-test and the t-test, and 95% CIs were determined. A p < 0.05 was considered statistically significant. RESULTS: Database search yielded 943 biopsies in 785 patients of which 65/943 (6.9%) reported LN as the highest risk pathologic lesion. Of 65 cases, 32 were found to have LN as the dominant finding on pathology and constituted the study population. All 32 findings were mammographically and sonographically occult. Three of 32 (9.3%) cases of lobular neoplasia were upgraded to malignancy, all LCIS (one pleomorphic and two classical). The most common MRI finding was focal, heterogenous non-mass enhancement with low T2 signal. No clinical features or imaging findings were predictive of upgrade to malignancy. CONCLUSION: Incidence of pure lobular neoplasia on MRI guided biopsy is low, with comparatively low incidence of upgrade to malignancy. No imaging or clinical features are predictive of upgrade on surgical excision, therefore, prudent radiologic-pathologic correlation is necessary.

Contrast-Enhanced Digital Mammography Screening for Intermediate-Risk Women With a History of Lobular Neoplasia.

OBJECTIVE. The objective of this study was to assess to the role of contrast-enhanced digital mammography (CEDM) as a screening tool in women at intermediate risk for developing breast cancer due to a personal history of lobular neoplasia without additional risk factors. MATERIALS AND METHODS. In this institutional review board-approved, observational, retrospective study, we reviewed our radiology department database to identify patients with a personal history of breast biopsy yielding lobular neoplasia who underwent screening CEDM at our institution between December 2012 and February 2019. A total of 132 women who underwent 306 CEDM examinations were included. All CEDM examinations were interpreted by dedicated breast imaging radiologists in conjunction with a review of the patient's clinical history and available prior breast imaging. In statistical analysis, sensitivity, specificity, NPV, positive likelihood ratio, and accuracy of CEDM in detecting cancer were determined, with pathology or 12-month imaging follow-up serving as the reference standard. RESULTS. CEDM detected cancer in six patients and showed an overall sensitivity of 100%, specificity of 88% (95% CI, 84-92%), NPV of 100%, and accuracy of 88% (95% CI, 84-92%). The positive likelihood ratio of 8.33 suggested that CEDM findings are 8.3 times more likely to be positive in an individual with breast cancer when compared with an individual without the disease. CONCLUSION. CEDM shows promise as a breast cancer screening examination in patients with a personal history of lobular neoplasia. Continued investigation with a larger patient population is needed to determine the true sensitivity and positive predictive value of CEDM for these patients.

The lobular neoplasia enigma: management and prognosis in a long follow-up case series.

BACKGROUND: Many oncologists debate if lobular neoplasia (LN) is a risk factor or an obligatory precursor of more aggressive disease. This study has three aims: (i) describe the different treatment options (surgical resection vs observation), (ii) investigate the upgrade rate in surgically treated patients, and (iii) evaluate the long-term occurrences of aggressive disease in both operated and unoperated patients. METHODS: A series of 122 patients with LN bioptic diagnosis and follow-up information were selected. Clinical, radiological, and pathological data were collected from medical charts. At definitive histology, either invasive or ductal carcinoma in situ was considered upgraded lesions. RESULTS: Atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), and high-grade LN (HG-LN) were diagnosed in 44, 63, and 15 patients, respectively. The median follow-up was 9.5 years. Ninety-nine patients were surgically treated, while 23 underwent clinical-radiological follow-up. An upgrade was observed in 28/99 (28.3%). Age ≥ 54 years (OR 4.01, CI 1.42-11.29, p = 0.009), Breast Imaging-Reporting and Data System (BI-RADS) categories 4-5 (OR 3.76, CI 1.37-10.1, p = 0.010), and preoperatory HG-LN diagnosis (OR 8.76, 1.82-42.27, p = 0.007) were related to upgraded/aggressive disease. During follow-up, 8 patients developed an ipsilateral malignant lesion, four of whom were not initially operated (4/23, 17%). CONCLUSIONS: BI-RADS categories 4-5, HG-LN diagnosis, and age ≥ 54 years were features associated with an upgrade at definitive surgery. Moreover, 17% of unoperated cases developed an aggressive disease, emphasizing that LN patients need close surveillance due to the long-term risk of breast cancer.

Impact of lobular carcinoma in situ on local recurrence in breast cancer treated with breast conservation therapy: a systematic review and meta-analysis.

BACKGROUND: Lobular carcinoma in situ (LCIS) is a known risk factor for breast cancer of unclear significance when detected in association with invasive carcinoma. This meta-analysis aims to determine the impact of LCIS on local recurrence risk for individuals with breast cancer treated with breast conservation therapy to help guide appropriate management strategies. METHODS: We identified relevant studies from five electronic databases. Studies were deemed suitable for inclusion where they compared patients with invasive breast cancer and concurrent LCIS to those with breast cancer alone, all patients underwent breast conservation therapy (lumpectomy with adjuvant radiation therapy) and local recurrence was evaluated. Recurrence data were pooled by use of a random-effects model. RESULTS: From 1488 citations screened by our search, nine studies were deemed suitable for inclusion. These studies comprised 990 cases and 12 870 controls. Median follow-up time was 104 months. There was a significantly increased risk of overall local recurrence of breast cancer for individuals with LCIS in association with breast cancer following breast conservation therapy (pooled odds ratio (pOR) 1.73; 95% confidence interval (CI) 1.10-2.71; P = 0.018). The risk of local recurrence was not significantly increased at 5 years (pOR 1.00; 95% CI 0.49-2.04; P = 0.995) and 10 years (pOR 1.52; 95% CI 0.72-3.23; P = 0.275). CONCLUSION: Individuals with LCIS in association with invasive breast cancer have an increased risk of local recurrence following breast conservation therapy. This supports consideration of increased medical surveillance and exploration of further risk reduction strategies for such patients.

Invasive lobular carcinoma of the breast: the increasing importance of this special subtype.

Invasive lobular carcinoma (ILC) is the most common of the breast cancer special types, accounting for up to 15% of all breast cancer cases. ILCs are noted for their lack of E-cadherin function, which underpins their characteristic discohesive growth pattern, with cells arranged in single file and dispersed throughout the stroma. Typically, tumours are luminal in molecular subtype, being oestrogen and progesterone receptor positive, and HER2 negative. Since last reviewing the lobular literature (McCart Reed et al., Breast Cancer Res 17:12, 2015), there has been a considerable increase in research output focused on this tumour type, including studies into the pathology and management of disease, a high-resolution definition of the genomic landscape of tumours as well as the evolution of several potential therapeutic avenues. There abounds a huge amount of new data, which we will review herein.

Classical Lobular Carcinoma In Situ Arising From an Intraductal Papilloma of the Breast: A Case Report.

Intraductal papilloma of the breast is a benign, mass-forming, proliferative lesion with a papillary architecture confined within a duct. Lobular neoplasia can rarely arise from an intraductal papilloma of the breast. In this article, we report the morphologic features of a rare case of classical LCIS (lobular carcinoma in situ) arising from an intraductal papilloma in a 76-year-old woman. The monomorphic dyscohesive cells were present between the myoepithelial and luminal epithelial layer in the periphery of the papilloma. These cells partially obliterated the spaces between the papillae forming solid sheets. The monomorphic dyscohesive cells showed lack of E-cadherin expression and uniform staining for estrogen receptor. We review the histologic differential diagnosis and stress the importance of correct classification to ensure optimal care for patients. We also propose a new criterion for the distinction of lobular neoplasia within a papilloma.

Lobular intraepithelial neoplasia: Outcomes and optimal management.

INTRODUCTION: Lobular neoplasia is a term encompassing both atypical lobular hyperplasia and lobular carcinoma in situ. These pathological findings are of uncertain malignant potential and predispose to a higher lifetime risk of breast cancer. Debate surrounds the management of such lesions, with the rationale for diagnostic excision based on the possibility of upgrading to malignancy. In this study, we report the upgrade rate of these lesions and risk of subsequent development of breast cancer. METHODS: This is a retrospective review of a prospectively maintained data base of all biopsies of breast screening-detected abnormalities in a single Irish breast-screening unit. We included all patients with lobular neoplasia on core needle biopsy who underwent diagnostic excision from 2005 to 2012. We excluded those who had concurrent high-risk lesions on biopsy. End points included upgrade rate and subsequent diagnosis of malignancy on follow-up. RESULTS: During the study period, 66 patients met criteria for inclusion, with a mean age of 53.74 years. Upgrade rate following excision was 13.64% (n = 9/66). Of those not upgraded, 7.02% (n = 4/57) were subsequently diagnosed with malignancy. Median time to diagnosis was 59.61 months (range = 10.5-124.4). CONCLUSION: There is a significant rate of upgrade following diagnostic excision of lobular neoplasia, supporting the practice of diagnostic excision. There is an increased lifetime risk of breast cancer for women with a diagnosis of lobular neoplasia, with many of these cancers occurring outside the standard five-year monitoring period, suggesting a potential benefit in extending surveillance.

Lobular neoplasia occult on conventional imaging and diagnosed on MRI-guided biopsy: can we estimate upgrade on surgical pathology?

PURPOSE: The goal of this study is to evaluate the frequency and imaging features of lobular neoplasia (LN) diagnosed on MRI-guided biopsy, determine the upgrade rate to malignancy, and assess for any features that may be associated with an upgrade on surgical excision. MATERIALS AND METHODS: Research ethical board approved the review of consecutive patients with MRI-detected LN between January 2009 and December 2018 with differentiation between pure LN and LN with associated other high-risk lesions. The final outcome was determined by final pathology results from surgical excision or 24 months of follow-up. Appropriate statistical tests were used. RESULTS: Out of 1250 MRI-guided biopsies performed, 76 lesions (6%) fulfilled the inclusion criteria and formed the study cohort. Of the 76 lesions, 54 (71%) were pure LN while the rest had coexistent high-risk lesion. Non-mass enhancement (NME) was the most common lesion type (62, 82%). Fifty-nine lesions (78%) were surgically excised, the other 17 had benign follow-up. Overall, 8 lesions (11%) were upgraded to malignancy on final pathology. Malignant outcome was associated with larger lesion size (5.5 versus 1.9 cm, P < 0.001) and a clumped NME pattern (75% versus 24%, P = 0.006). Lesion size and clumped NME remained significantly associated with upgrade on sub-analysis of the pure LN group. CONCLUSION: Larger lesion size and clumped NME are imaging findings associated with upgrade of LN diagnosed by MRI-guided biopsy. This may influence patient management in this clinical setting. Additional larger studies are needed to consolidate our results and to potentially detect additional factors associated with upgrade.

Risk for Upgrade to Malignancy After Breast Core Needle Biopsy Diagnosis of Lobular Neoplasia: A Systematic Review and Meta-Analysis.

PURPOSE: Lobular neoplasia (LN) detected on breast core needle biopsy is frequently managed with surgical excision because of concern for undersampled malignancy. The authors performed a systematic review and meta-analysis to estimate the risk for upgrade to malignancy in the setting of imaging-concordant classic LN diagnosed on core biopsy. METHODS: PubMed and Embase were searched for original articles published from 1998 to 2020 that reported rates of upgrade to malignancy for classic LN, including atypical lobular hyperplasia (ALH) and classic lobular carcinoma in situ (LCIS). Two reviewers extracted study data and assessed the following quality criteria: exclusion of variant LCIS, exclusion of imaging-discordant lesions, and outcome reporting for ≥70% of lesions. For studies meeting all criteria, pooled risks for upgrade to any malignancy (invasive carcinoma or ductal carcinoma in situ) and invasive malignancy for all LN, ALH, and LCIS were estimated using random-effects models. RESULTS: For 65 full-text articles included in the review, the risk for upgrade to any malignancy ranged from 0% to 45%. Among the 16 studies that met all quality criteria for the meta-analysis, pooled risks for upgrade to any malignancy were 3.1% (95% confidence interval [CI], 1.8%-5.2%) for all LN, 2.5% (95% CI, 1.6%-3.9%) for ALH, and 5.8% (95% CI, 2.9%-11.3%) for LCIS. Risks for upgrade to invasive malignancy were 1.3% (95% CI, 0.7%-2.4%) for all LN, 0.4% (95% CI, 0.0%-4.2%) for ALH, and 3.5% (95% CI, 2.0%-5.9%) for LCIS. CONCLUSIONS: The risk for upgrade to malignancy for LN found on breast biopsy is low. Imaging surveillance can likely be offered as an alternative to surgical management for LN, particularly for ALH.

Inter-observer reproducibility of classical lobular neoplasia (B3 lesions) in preoperative breast biopsies: a study of the Swiss Working Group of breast and gynecopathologists.

PURPOSE: Classical type of lobular neoplasia (LN) spans a spectrum of disease, including atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), classical lobular neoplasia (LN), and the three-tiered classification of lobular intraepithelial neoplasia (LIN-1, -2, -3). This study addressed inter-observer variability of classical lobular neoplasias (LN) (B3 lesions) in preoperative breast biopsies among breast and gynecopathologists METHODS: A retrospective, observational, cross-sectional study was conducted. 40 preoperative digital images of breast core/vacuum biopsies were analyzed by eight experienced breast- and gynecopathologists. Evaluation criteria were ALH, LCIS, LN classic, LIN-1, LIN-2, LIN-3, focal B3 (one focus), extensive B3 (> one focus). Kappa-index and Chi-square tests were used for statistics. Digital scanned slides were provided to each participant. Agreement between the categories was defined as at least six of eight (cut-off 75%) concordant diagnoses. RESULTS: The highest agreement between eight pathologists was reached using the category lobular neoplasia (LN, classical), 26/40 (65%) cases were diagnosed as such. Agreements in other categories was low or poor: 12/40 (30%) (ALH), 9/40 (22%) (LCIS), 8/40 (20%) (LIN-1), 8/40 (20%) (focal B3), 3/40 (7.5%) (LIN-2), and 2/40 (5%) (extensive B3). Chi-square-test (classical LN versus the other nomenclatures) was significant (p = 0.001137). CONCLUSION: Our data suggest that among Swiss breast pathologists, the most reproducible diagnosis for B3 lobular lesions is the category of classical LN. These data further support lack of consistent data in retrospective studies using different terminologies. Validation of reproducible nomenclature is warranted in further studies. This information is useful especially in view of retro- and prospective data analysis with different diagnostic categories.

Outcomes of classic lobular neoplasia diagnosed on breast core needle biopsy: a retrospective multi-center study.

Management of classic lobular neoplasia (cLN) diagnosed on core needle biopsy (CNB) is controversial. Our aim in this study was to review cases of cLN diagnosed on CNB to determine the rate and risk factors of an upgrade to ductal carcinoma in situ (DCIS) or invasive carcinoma on excision. All breast CNBs with a diagnosis of atypical lobular hyperplasia (ALH) or classic lobular carcinoma in situ (cLCIS) from three different institutions within a single health care system between 2013 and 2018 were retrieved. Cases with any additional high-risk lesions in the same CNB or discordant radiological-pathological correlation were excluded. Information about age, personal history of prior or concurrent breast cancer (P/CBC), and radiological and histological findings were recorded. A total of 287 cLN cases underwent surgical excision. Analysis of these 287 cLN cases showed 11 (3.8%) upgrade lesions on excision. Among the 172 ALH cases, there were 3 (1.7%) upgrades, which were all invasive lobular carcinomas (ILCs). On the other hand, 8 of 115 (7%) cLCIS cases revealed upgrade on excision (2 ILC, 5 DCIS. and 1 ILC + DCIS). Statistical analysis revealed that cLN cases with P/CBC, radiological asymmetry, or architectural distortion had a statistically significant higher upgrade rate on excision. Our findings revealed a low upgrade rate (3.8%) on the excision of classic lobular neoplasia diagnosed on breast core needle biopsy. Clinicoradiological surveillance can be appropriate when lobular neoplasia is identified on core biopsy with pathological radiological concordance in patients without a history of breast cancer, with the caveat that radiological asymmetry and architectural distortion are associated with a significant increase in an upgrade on excision.