Lobular neoplasia: morphology, biological potential and management in core biopsies

The Challenges of Lobular Carcinomas from a Surgeon's Point of View

Invasive lobular breast cancer (ILC) presents unique challenges and considerations in the realm of surgical management. Characterized by its distinct histological features, including the loss of E-cadherin expression and dys-cohesive growth pattern, ILC often poses diagnostic and therapeutic dilemmas for clinicians. This abstract explores the surgical landscape of ILC, focusing on its epidemiology, clinical presentation, diagnostic modalities, and surgical interventions. Emphasizing the importance of individualized treatment strategies, this narrative delves into the nuances of surgical decision-making, including the role of breast-conserving surgery versus mastectomy, axillary staging, and the significance of margin status. Additionally, advancements in surgical techniques, such as oncoplastic approaches and sentinel lymph node biopsy, are examined in the context of optimizing oncologic outcomes and preserving cosmesis. Through a comprehensive review of current literature and clinical guidelines, this overview aims to provide a nuanced understanding of the surgical considerations inherent to the management of invasive lobular breast cancer.

Updates in the Surgical Management of Benign and High-Risk Breast Lesions

Benign breast disease (BBD) is a heterogenous group of lesions often classified as nonproliferative or proliferative, with the latter group further categorized based on the presence of atypia. Although nonproliferative lesions are more common, the risk of breast cancer is elevated in women with proliferative lesions. Historically, the majority of proliferative lesions were excised due to concern for future and/or concomitant breast cancer at the site of the index lesion. However, contemporary data suggest that the risk of cancer associated with various proliferative lesions may be lower than previously thought, and management of BBD has become more nuanced. In this review, we will focus on recent updates in the management of a select group of benign and high-risk lesions.

Upgrade rate to malignancy of uncertain malignant potential breast lesions (B3 lesions) diagnosed on vacuum-assisted biopsy (VAB) in screen detected microcalcifications: Analysis of 366 cases from a single institution

PURPOSE

We retrospectively investigated clinical, radiological, and pathological features of B3 lesions associated with the risk of subsequent upgrade to malignancy.

METHODS

We included consecutive vacuum-assisted biopsies (VABs) performed during 2011-2020 on suspicious microcalcifications not associated with other radiological signs diagnosed as B3 lesions and followed by surgical excision (SE) with definitive histological examination. Multiple logistic regression models were fitted to identify independent predictors of malignancy.

RESULTS

Out of the 366 B3 lesions included, 56 (15.3 %, 95 % CI 11.8-19.4 %) had upgraded to malignancy at SE: of these, 42/366 (11.5 %, 95 % CI 8.4-15.2 %) and 14/366 (3.8 %, 95 % CI 2.1-6.3 %) were in situ and invasive carcinoma, respectively. At univariate analysis, variables positively associated with upgrade to malignancy were age ≥ 60 years (p = 0.008), mixed morphology (p = 0.018), scattered distribution (p = 0,001), extension of microcalcifications > 10 mm (p = 0.001), and mixed B3 lesion (p = 0.017). Among B3 subtypes, the highest rates of upgrade were observed for AIDEP, LCIS/LIN2, FEA + AIDEP, FEA + LCIS/LIN2, and FEA + AIDEP + LCIS/LIN2 (24.6 %, 21.4 %, 25.3 %, 20.0 % and 40.0 % respectively), while FEA and ALH/LIN1 had a lower rates of upgrade (7.5 % and 3.7 %, respectively). Multiple logistic regression analysis confirmed as risk factors older age (p = 0.029), larger extension (p = 0.001) and mixed morphology (p = 0.007) of microcalcifications, AIDEP (p = 0.011) among pure B3 lesions, and FEA + AIDEP (p = 0.001) and FEA + AIDEP + LCIS/LIN2 (p = 0.037) among mixed B3 lesions.

CONCLUSIONS

Based on our findings, vacuum-assisted excision is reasonable as definitive management for FEA and ALH/LIN1, while SE should remain the mainstay of treatment for AIDEP and LCIS/LIN2, whose upgrade rates are too high to safely recommend VAE.

Malignancy Rate and Malignancy Risk Assessment in Different Lesions of Uncertain Malignant Potential in the Breast (B3 Lesions): An Analysis of 192 Cases from a Single Institution

BACKGROUND

The question of how to deal with B3 lesions is of emerging interest.

METHODS

In the breast diagnostics of 192 patients between 2009 and 2016, a minimally invasive biopsy revealed a B3 lesion with subsequent resection. This study investigates the malignancy rate of different B3 subgroups and the risk factors that play a role in obtaining a malignant finding.

RESULTS

The distribution of B3 lesions after minimally invasive biopsy was as follows: atypical ductal hyperplasia (ADH), 7.3%; flat epithelial atypia (FEA), 7.8%; lobular neoplasia (LN), 7.8%; papilloma (Pa), 49.5%; phylloidal tumour (PT), 8.9%; radial sclerosing scar (RS), 3.1%; mixed findings, 10.4%; and other B3 lesions, 5.2%. Most B3 lesions were detected by stereotactic vacuum-assisted biopsy (44.3%), 36.5% by ultrasound-assisted biopsy, and 19.3% by magnetic resonance imaging-assisted biopsy. Most B3 lesions (55.2%) were verified by surgical resection, whereas 30.7% were downgraded to a benign lesion. About 14.1% of the cases were upgraded to malignant lesions, 9.4% to ductal carcinoma in situ and 4.7% to invasive carcinoma. In relation to individual B3 lesions, the following malignancy rates were found: 28.6% (ADH), 13.3% (FEA), 33.3% (LN), 12.6% (Pa), 5.9% (PT), and 0% (RS). The most important risk factor was increasing age. Postmenopausal status was considered an increased risk for an upgrade (p = 0.015). A known malignancy in the ipsilateral breast was a significant risk factor for a malignant upgrade (p = 0.003).

CONCLUSION

Increasing knowledge about B3 lesions allows us to develop a "lesion-specific" therapy approach in the heterogeneous group of B3 lesions, with follow-up imaging for some lesions with less malignant potential and concordance with imaging or further surgical resection in cases of disconcordance with imaging or higher malignant potential.

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.

[Histological lesions of risk of breast carcinoma. Survival guide for the general pathologist]

Proliferative epithelial lesions are risk factors for breast cancer. They are a heterogeneous group of lesions in which the presence of atypia is related to varying degrees of risk. They should be considered in the differential diagnosis with benign lesions, in situ ductal carcinoma and infiltrating carcinoma. An accurate histopathological diagnosis is important in choosing the best therapeutic option, including vacuum assisted biopsy and surgery. We revise diagnostic criteria and the differential diagnosis of usual ductal hyperplasia, radial scar and complex sclerosing lesions, distinct types of adenosis, papillary lesions, atypical ductal hyperplasia, flat epithelial atypia and lobular neoplasia in situ. Furthermore, we summarize the degree of risk associated with the different conditions and management possibilities.

Excision or Observation: The Dilemma of Managing High-Risk Breast Lesions

There is an enduring dilemma on the appropriate management of high-risk breast lesions; is surgical excision always warranted or can conservative management be utilized? We present cases of high-risk breast lesions diagnosed at core needle biopsy at our institution along with relevant factors to consider for appropriate management. We conclude that a nuanced approach is warranted over the broad stroke approach of surgical excision of all high-risk breast lesions.

Pleomorphic LCIS what do we know? A UK multicenter audit of pleomorphic lobular carcinoma in situ

AIMS

Pleomorphic lobular carcinoma in situ (PLCIS) is a relatively newly described pathological lesion that is distinguished from classical LCIS by its large pleomorphic nuclei. The lesion is uncommon and its appropriate management has been debated. The aim of this study is to review data from a large series of PLCIS to examine its natural history in order to guide management plans.

MATERIALS AND METHODS

Comprehensive pathology data were collected from two cohorts; one from a UK multicentre audit and the other a series of PLCIS cases identified from within the GLACIER study cohort. 179 cases were identified of whom 176 had enough data for analysis.

RESULTS

Out of these 176 cases, 130 had invasive disease associated with PLCIS, the majority being of lobular type (classical and/or pleomorphic). A high incidence of histological grade 2 and 3 invasive cancers was noted with a predominance of ER positive and HER-2 negative malignancy. When PLCIS was the most significant finding on diagnostic biopsy the upgrade to invasive disease on excision was 31.8%, which is higher than pooled data for classical LCIS and DCIS.

CONCLUSION

The older age at presentation, high grade of upgrade to invasive cancer, common association with higher grade tumours suggest that PLCIS is an aggressive form of insitu disease. These findings support the view that PLCIS is a more aggressive form of lobular in situ neoplasia and supports the tendency to treat akin to DCIS.

Treatment and survival outcomes of lobular carcinoma in situ of the breast: a SEER population based study

Lobular carcinoma in situ (LCIS) represents 5.3% of in situ specimens, and is thought to carry a low risk for developing to the invasive lobular breast cancer (ILC). There is still no standard care approach for patients with LCIS. We aimed to define the impacts of surgical and radiation intervention on survival outcomes of LCIS. LCIS cases from 2004 to 2013 of the recent Surveillance, Epidemiology, and End Results (SEER) database were analyzed. Clinicopathologic features were analyzed in 16002 patients between 2004 and 2013. Treatment modalities included no surgery (NS), lumpectomy alone (LA), lumpectomy with radiation treatment (LRT), mastectomy alone (MA) and mastectomy with radiation treatment (MRT). The overall survival (OS) was calculated by the Kaplan-Meier method. Univariate and multivariate analyses were performed using the variables of treatment, race, hormone receptor status, grade and age. Among 16002 patients, median follow-up was 54 months. Patients treated with LA had superior OS for NS (P = 0.001), MA (P < 0.001) and MRT P = 0.018). LRT only had superior OS for MRT (P = 0.009). There was no statistically significance between LA and LRT (P = 0.317). Improved OS was also correlated with younger age (P < 0.001), progesterone receptor positive (P = 0.001). Black patients had the worst OS (P < 0.001). There was no obvious survival difference among grade groups (P = 0.536). The LCIS patients treated with LA or LRT had better survival comparing with other groups. Considering the medical expense and the risk of radiotherapy, LA may be the most appropriate therapy for patients with LCIS.

Carcinoma in situ of the breast in New South Wales, Australia: Current status and trends over the last 40 year

BACKGROUND

The incidence of non-invasive breast cancer has increased substantially over time. We aim to describe temporal trends in the incidence of carcinoma in situ of the breast in New South Wales (NSW), Australia.

METHODS

Descriptive study of trends in the incidence of ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) in women who received a diagnosis from 1972 to 2012, recorded in the NSW Cancer Registry.

RESULTS

Carcinoma in situ as a proportion of all breast cancer was 0.4% during the prescreening period 1972 to 1987 and is currently 14.1% (2006 to 2012). Among 10,810 women diagnosed with DCIS, incidence across all ages rose from 0.15 per 100,000 during 1972 to 1983 to 16.81 per 100,000 over 2006 to 2012, representing a 100-fold increase (IRR 113.10; 95% CI 81.94 to 156.08). Among women in the target age group for screening (50-69 years) incidence rose from 0.27 per 100,000 to 51.96 over the same period (IRR 195.50; 95% CI 117.26 to 325.89). DCIS incidence peaks in women aged 60-69 years. DCIS incidence has not stabilized despite screening being well established for over 20 years, and participation rates in the target age range remaining stable.

CONCLUSIONS

Our findings raise questions about the value of the increasing detection of DCIS and aggressive treatment of these lesions, especially among older women, and support trials of de-escalated treatment.

Pleomorphic lobular carcinoma in situ of the breast: a single institution experience with clinical follow-up and centralized pathology review

PURPOSE

The natural history of pleomorphic lobular carcinoma in situ (PLCIS) remains largely unknown.

METHODS

A pathology database search (1995-2012) was performed to identify patients diagnosed with an LCIS variant. Patients with synchronous breast cancer and/or no evidence of pleomorphism were excluded. Original slides were re-evaluated by three pathologists to identify a consensus cohort of PLCIS. Borderline lesions with focal atypia were classified as LCIS with pleomorphic features (LCIS-PF). Clinical data were obtained from medical records.

RESULTS

From 233 patients, we identified 32 with an LCIS variant diagnosis and no concurrent breast cancer. Following review, 16 cases were excluded due to lack of pleomorphism. The remaining 16 were classified as PLCIS (n = 11) and LCIS-PF (n = 5). 12/16 patients were treated with surgical excision ± chemoprevention. Patients with a prior breast cancer history and those having mastectomy were excluded from outcome analysis. Among the remaining 7 patients with PLCIS/LCIS-PF, 4/7 (57%) developed ipsilateral breast cancer at a median follow-up of 67 months. Median age at the time of breast cancer diagnosis was 56 years old and median time from PLCIS/LCIS-PF to cancer diagnosis was 59 months (range 45-66 months). The four cancers included 1 invasive lobular carcinoma (ILC), 1 microinvasive ILC, 1 invasive ductal carcinoma, and 1 ductal carcinoma in situ.

CONCLUSIONS

We confirm that PLCIS in isolation is indeed a rare entity, further contributing to the difficulty in determining the actual risk conferred by this lesion. Long-term follow-up data on larger cohorts are needed to define standardized management and outcomes for patients with PLCIS.

Core Breast Biopsies Showing Lobular Carcinoma In Situ Should Be Excised and Surveillance Is Reasonable for Atypical Lobular Hyperplasia

OBJECTIVE

The purpose of this article is to determine the upgrade rate to ductal carcinoma in situ (DCIS) or invasive carcinoma at excision at the same site after percutaneous breast biopsy findings of atypical lobular hyperplasia (ALH) or lobular carcinoma in situ (LCIS) using current imaging and strict pathologic criteria.

MATERIALS AND METHODS

From January 2006 through September 2013, 32,960 breast core biopsies were performed; 1084 (3.3%) core biopsies found ALH or classic LCIS. For 447 lesions in 433 women, this was the only high-risk lesion at that site, with no ipsilateral malignancy, and results of excision were available.

RESULTS

Among the 447 lesions, 22 (4.9%) were malignant at excision, including 10 invasive carcinomas (two grade 2 and eight grade 1; all node negative) and 12 DCIS. The upgrade rate of LCIS was 9.3% (10/108; 95% CI, 5.1-16.2%) and that of ALH was 3.5% (12/339; 95% CI, 2.0-6.1%; p = 0.02). After excluding five cases with radiologic-pathologic discordance and reclassifying one core from ALH to LCIS at review, the upgrade rate for LCIS remained higher (8.4%; 9/107; 95% CI, 4.5-15.2%) than that for ALH (2.4%; 8/335; 95% CI, 1.2-4.6%; p = 0.01).

CONCLUSION

Excision is recommended for LCIS on core biopsy because of its 8.4-9.3% upgrade rate. Excluding discordant cases, patients with other high-risk lesions or concurrent malignancy, the risk of upgrade of ALH was 2.4%. Surveillance at 6, 12, and 24 months can be performed in lieu of excision because a short delay in diagnosis of the few malignancies is not expected to cause harm.

Bioanalytical LC-MS Method for the Quantification of Plasma Androgens and Androgen Glucuronides in Breast Cancer

The physiological and pathological development of the breast is strongly affected by the hormonal milieu consisting of steroid hormones. Mass spectrometry (MS) technologies of high sensitivity and specificity enable the quantification of androgens and consequently the characterization of the hormonal status. The aim of this study is the assessment of plasma androgens and androgen glucuronides, in the par excellence hormone-sensitive tissue of the breast, through the application of liquid chromatography-mass spectrometry (LC-MS). A simple and efficient fit-for-purpose method for the simultaneous identification and quantification of dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), androsterone glucuronide (ADTG) and androstane-3α, 17β-diol-17-glucuronide (3α-diol-17G) in human plasma was developed and validated. The presented method permits omission of derivatization, requires a single solid-phase extraction procedure and the chromatographic separation can be achieved on a single C18 analytical column, for all four analytes. The validated method was successfully applied for the analysis of 191 human plasma samples from postmenopausal women with benign breast disease (BBD), lobular neoplasia (LN), ductal carcinoma in situ and invasive ductal carcinoma (IDC). DHEAS plasma levels exhibited significant differences between LN, IDC and BBD patients (P < 0.05). Additionally, ADTG levels were significantly higher in patients with LN compared with those with BBD (P < 0.05).

Lobular neoplasia detected in MRI-guided core biopsy carries a high risk for upgrade: a study of 63 cases from four different institutions

There are certain criteria to recommend surgical excision for lobular neoplasia diagnosed in mammographically detected core biopsy. The aims of this study are to explore the rate of upgrade of lobular neoplasia detected in magnetic resonance imaging (MRI)-guided biopsy and to investigate the clinicopathological and radiological features that could predict upgrade. We reviewed 1655 MRI-guided core biopsies yielding 63 (4%) cases of lobular neoplasia. Key clinical features were recorded. MRI findings including mass vs non-mass enhancement and the reason for biopsy were also recorded. An upgrade was defined as the presence of invasive carcinoma or ductal carcinoma in situ in subsequent surgical excision. The overall rate of lobular neoplasia in MRI-guided core biopsy ranged from 2 to 7%, with an average of 4%. A total of 15 (24%) cases had an upgrade, including 5 cases of invasive carcinoma and 10 cases of ductal carcinoma in situ. Pure lobular neoplasia was identified in 34 cases, 11 (32%) of which had upgrade. In this group, an ipsilateral concurrent or past history of breast cancer was found to be associated with a higher risk of upgrade (6/11, 55%) than contralateral breast cancer (1 of 12, 8%; P=0.03). To our knowledge, this is the largest series of lobular neoplasia diagnosed in MRI-guided core biopsy. The incidence of lobular neoplasia is relatively low. Lobular neoplasia detected in MRI-guided biopsy carries a high risk for upgrade warranting surgical excision. However, more cases from different types of institutions are needed to verify our results.

Cancer statistics: Breast cancer in situ

An estimated 60,290 new cases of breast carcinoma in situ are expected to be diagnosed in 2015, and approximately 1 in 33 women is likely to receive an in situ breast cancer diagnosis in her lifetime. Although in situ breast cancers are relatively common, their clinical significance and optimal treatment are topics of uncertainty and concern for both patients and clinicians. In this article, the American Cancer Society provides information about occurrence and treatment patterns for the 2 major subtypes of in situ breast cancer in the United States-ductal carcinoma in situ and lobular carcinoma in situ-using data from the North American Association of Central Cancer Registries and the 13 oldest Surveillance, Epidemiology, and End Results registries. The authors also present an overview of in situ breast cancer detection, treatment, risk factors, and prevention and discuss research needs and initiatives.

Multinucleation is an objective feature useful in the diagnosis of pleomorphic lobular carcinoma in situ

OBJECTIVES

Bi- and multinucleated (B/M) cells are present in a variety of tumors. We evaluated lobular carcinoma in situ (classic and pleomorphic types) and ductal carcinoma in situ (DCIS) to determine if this objective morphologic feature aids the differential diagnosis.

METHODS

The number of B/M cells was recorded in pleomorphic lobular carcinoma in situ (PLCIS) (n = 20), classic lobular carcinoma in situ (CLCIS) (n = 26), and DCIS (n = 37).

RESULTS

Binucleated cells were significantly more frequent in PLCIS (100%) vs DCIS (43%; P < .0001) and CLCIS (54%; P = .0004). Multinucleated cells were present in 25% of PLCIS cases and 8% of DCIS cases, and they were absent in CLCIS. The quantity of B/M per high-power field (hpf) was less in DCIS (mean, 1.1) and CLCIS (mean, 2.5) compared with PLCIS (mean, 5.8). Thirty-five percent of PLCIS cases had more than five B/M per hpf.

CONCLUSIONS

Binucleated cells are significantly more frequent in PLCIS vs CLCIS and DCIS. Multinucleated cells were never identified in CLCIS. PLCIS should be considered as a diagnosis when B/M is noted.

Inter-observer variability between general pathologists and a specialist in breast pathology in the diagnosis of lobular neoplasia, columnar cell lesions, atypical ductal hyperplasia and ductal carcinoma in situ of the breast

Background

This study aimed to assess inter-observer variability between the original diagnostic reports and later review by a specialist in breast pathology considering lobular neoplasias (LN), columnar cell lesions (CCL), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS) of the breast.

Methods

A retrospective, observational, cross-sectional study was conducted. A total of 610 breast specimens that had been formally sent for consultation and/or second opinions to the Breast Pathology Laboratory of Federal University of Minas Gerais were analysed between January 2005 and December 2010. The inter-observer variability between the original report and later review was compared regarding the diagnoses of LN, CCL, ADH, and DCIS. Statistical analyses were conducted using the Kappa index.

Results

Weak correlations were observed for the diagnoses of columnar cell change (CCC; Kappa = 0.38), columnar cell hyperplasia (CCH; Kappa = 0.32), while a moderate agreement (Kappa = 0.47) was observed for the diagnoses of flat epithelial atypia (FEA). Good agreement was observed in the diagnoses of atypical lobular hyperplasia (ALH; Kappa = 0.62) and lobular carcinoma in situ (LCIS; Kappa = 0.66). However, poor agreement was observed for the diagnoses of pleomorphic LCIS (Kappa = 0.22). Moderate agreement was observed for the diagnoses of ADH (Kappa = 0.44), low-grade DCIS (Kappa = 0.47), intermediate-grade DCIS (Kappa = 0.45), and DCIS with microinvasion (Kappa = 0.56). Good agreement was observed between the diagnoses of high-grade DCIS (Kappa = 0.68).

Conclusions

According to our data, the best diagnostic agreements were observed for high-grade DCIS, ALH, and LCIS. CCL without atypia and pleomorphic LCIS had the worst agreement indices.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1640072350119725.

Underestimation rate of lobular intraepithelial neoplasia in vacuum-assisted breast biopsy

OBJECTIVES

To evaluate the underestimation rate and clinical relevance of lobular neoplasia in vacuum-assisted breast biopsy (VABB).

METHODS

A total of 161 cases of LN were retrieved from 6,435 VABB. The histological diagnosis was ALH (atypical lobular hyperplasia) in 80 patients, LCIS (lobular carcinoma in situ) in 69 patients and PLCIS (pleomorphic lobular carcinoma in situ) in 12 patients. Seventy-six patients were operated on within 2 years after VABB and 85 were clinically and radiologically monitored. The mean follow-up was 5.2 years, and the prevalence of malignancy was evaluated in the group of 85 patients.

RESULTS

The clinico-pathological characteristics significantly favouring surgery were larger lesions, occurrence of a residual lesion following VABB and histological LCIS and PLCIS subtypes. The VABB underestimation rate as compared to surgery was 7.1% for ALH, 12% for LCIS and 50% for PLCIS. Overall, 11 of the 148 patients included in this survival analysis developed an ipsilateral tumour.

CONCLUSION

Although obtained retrospectively in a relatively small series of patients, our data suggest that only patients with a diagnosis of PLCIS in VABB should be treated with surgery, whereas patients with ALH and LCIS could be monitored by clinical and radiological examinations.

KEY POINTS

• The treatment of ALH and LCIS in VABB is still debated • Some authors favour radical treatment and others a more conservative approach • Only patients with PLCIS in VABB should be treated by surgery.

Breast cancer precursors: diagnostic issues and current understanding on their pathogenesis

The development of breast malignancy has been recognised to progress through a number of morphological precursor lesions. More recently, specific molecular alterations have been recognised in these precursor lesions. These changes appear to determine a specific malignant phenotype, which in turn, may realign the current opinion on the classification of breast cancer along molecular characteristics. This review will highlight the morphological features of these precursor lesions and their relationship to the complex molecular processes involved in their development.

Morphological parameters of lobular in situ neoplasia in stereotactic 11-gauge vacuum-assisted needle core biopsy do not predict the presence of malignancy on subsequent surgical excision

AIMS

The management of lobular in situ neoplasia (LN) when diagnosed on core biopsy remains a controversial issue. The present study aimed to investigate the association between morphological parameters of LN on vacuum-assisted needle core biopsy (VANCB) and the presence of malignancy (ductal carcinoma in situ, pleomorphic lobular carcinoma in situ, or invasive carcinoma) at surgical excision (SE).

METHODS AND RESULTS

The study included 14 pathology departments in Italy. Available slides from 859 cases of VANCB reporting an original diagnosis of flat epithelial atypia, atypical ductal hyperplasia or LN, all with subsequent surgical excision, were reviewed. Overall, 286 cases of LN, pure or associated with other lesions, were identified, and a malignant outcome was reported at excision for 51 cases (17.8%). Among the 149 cases of pure LN, an increased risk of malignancy emerged in women in mammographic categories R4-R5 as compared with those in categories R2-R3 (OR 2.46; P = 0.048). In the series, a statistically significant decreased malignancy risk emerged among cases without determinant microcalcifications (P = 0.04).

CONCLUSIONS

Our results suggest that the diagnosis of pure LN on VANCB warrants follow-up excision, because clinicopathological parameters do not allow the prediction of which cases will present carcinoma at surgical excision.

Relapsed classic E-cadherin (CDH1)-mutated invasive lobular breast cancer shows a high frequency of HER2 (ERBB2) gene mutations

PURPOSE

We queried whether comprehensive genomic profiling using a next-generation sequencing-based assay could identify novel and unanticipated targets of therapy for patients with relapsed invasive lobular carcinoma (ILC).

EXPERIMENTAL DESIGN

DNA sequencing (Illumina HiSeq 2000) was conducted for 3,320 exons of 182 cancer-related genes and 37 introns of 14 genes frequently rearranged in cancer on indexed, adaptor-ligated, hybridization-captured libraries using DNA isolated from formalin-fixed paraffin-embedded sections from 22 histologically verified ILC.

RESULTS

A total of 75 genomic alterations were identified with an average of 3.4 alterations per tumor (range, 1-6), of which 35 were actionable for an average of 1.59 actionable alterations per patient (range, 0-3). Nineteen of 22 (86%) of the ILC samples harbored at least one actionable alteration. Six (27%) cases featured alterations in ERRB2 including 4 (18%) with ERBB2 mutation, 1 (5%) with an ERBB2 gene fusion, and 1 (5%) with an ERBB2 copy number gain (amplification). The enrichment of ERBB2 mutations/fusion in CDH1-mutated ILC (5 of 22, 23%) compared with the 5 ERBB2 mutations in a series of 286 non-CDH1-mutated breast cancers from which the ILC cases were obtained (5 of 286, 2%) was significant (P = 0.0006).

CONCLUSIONS

Comprehensive genomic profiling of relapsed CDH1-mutated ILC revealed actionable genomic alterations in 86% of cases, featured a high incidence of ERBB2 alterations, and can reveal actionable alterations that can inform treatment decisions for patients with ILC.

Microinvasive lobular carcinoma arising in a fibroadenoma

A 51-year-old woman had a 35 mm circumscribed calcified lesion identified on screening mammography, designated R4. Excision showed a fibroadenoma with multiple foci of lobular neoplasia (atypical lobular hyperplasia and classical lobular carcinoma in situ [LCIS]). A focus of microinvasive lobular carcinoma (MILC) was also present, confirmed on immunohistochemistry. The MILC cells were ER positive, Her-2-negative, and e-cadherin negative. Microinvasive carcinoma, defined as "invasive carcinoma with no focus measuring >1 mm" (TNM UICC 7th edition) is usually encountered in ductal carcinoma in situ but may occur with classical, florid, or pleomorphic LCIS. In one series MILC constituted 0.4% of all invasive lobular carcinomas and was present in 0.4% of all LCIS. MILC is a histologically subtle lesion, the identification of which lends further weight to the concept of lobular neoplasia as a precursor lesion. MILC has been observed in hamartoma but, to our knowledge, has not previously been reported in fibroadenoma.

The management of preinvasive breast cancer

SUMMARY Ductal carcinoma in situ (DCIS) is a preinvasive breast cancer in which the proliferations of malignant ductal epithelial cells have not breached the ductal basement membrane. Currently there is controversy over the optimum management of DCIS, with suggestions that there may be an element of ‘overdiagnosis’ of some low-risk cases that may never progress to invasive cancer within a patient’s lifetime. This review discusses the biology and natural history of DCIS and current management strategies, addresses the risk factors for recurrence and how these can be minimized, highlights areas of controversy and suggest the possible direction of future research.

Low frequency of cancer occurrence in same breast quadrant diagnosed with lobular neoplasia at percutaneous needle biopsy

PURPOSE

To determine the type of mammographic abnormality leading to needle biopsy of lobular neoplasia (LN) and define the clinical evolution of low-risk LN lesions diagnosed at needle biopsy but not surgically removed.

MATERIALS AND METHODS

This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. Among 16 945 needle biopsies performed between April 1998 and August 2008, LN was determined to be the most suspicious lesion in 352 samples (2.1%) (pleomorphic and necrotic forms were excluded). Among 299 pure LN lesions that were not surgically removed, follow-up was available for 276 lesions in 275 women.

RESULTS

Needle biopsy was performed because of mammographic calcifications in 215 of the 276 lesions (77.9%) and because of mammographic masses in 35 (12.7%). The mean follow-up was 5.0 years ± 2.4 (range, 0.6-12.2 years). All 275 women underwent one mammographic follow-up, 205 (74.5%) underwent a second mammographic follow-up, and 147 (53.5%) underwent a third mammographic follow-up. Cancer was diagnosed in 27 of the 275 cases (9.8%) after a mean of 3.9 years ± 2.6 (range, 1.2-10.8 years). Only three cancers (1.1%) occurred in the same breast quadrant as the one originally diagnosed with LN at needle biopsy.

CONCLUSION

Lumpectomy of pure LN lesions may not prevent malignancy in most cases. Consequently, women with pure LN of a low-risk type diagnosed at needle biopsy are strongly encouraged to undergo a yearly breast clinical examination and yearly mammographic follow-up to detect an eventual cancer in its early stages.

Clinicopathologic and immunohistochemical characteristics of male breast cancer: a single center experience

Male breast cancer (MaleBC) is a rare tumor that has been insufficiently described in the Middle East. The purpose of this study is to report the first MaleBC series in Lebanon, describing its clinicopathologic and immunohistochemical phenotype, and how it compares with MaleBC in the West and with female breast cancer in Lebanon and the Middle East. Forty-seven cases of MaleBC were reviewed. Results showed younger ages at presentation (62 years versus 67 years), higher incidence of lobular carcinoma (6% versus 1%), and more frequent p53 positivity and axillary node metastases in our series than in those reported about MaleBC. Other results such as higher estrogen receptor (ER) positivity and lower HER-2/neu over-expression were comparable to the literature. These findings suggest that MaleBC in our region may represent a biologically different tumor with potentially distinct prognostic and therapeutic implications.

Hsa-miR-375 is differentially expressed during breast lobular neoplasia and promotes loss of mammary acinar polarity

Invasive lobular carcinoma (ILC) of the breast, characterized by loss of E-cadherin expression, accounts for 5-15% of invasive breast cancers and it is believed to arise via a linear histological progression. Genomic studies have identified a clonal relationship between ILC and concurrent lobular carcinoma in situ (LCIS) lesions, suggesting that LCIS may be a precursor lesion. It has been shown that an LCIS diagnosis confers a 15-20% risk of progression to ILC over a lifetime. Currently no molecular test or markers can identify LCIS lesions likely to progress to ILC. Since microRNA (miRNA) expression changes have been detected in a number of other cancer types, we explored whether their dysregulation might be detected during progression from LCIS to ILC. Using the Illumina miRNA profiling platform, designed for simultaneous analysis of 470 mature miRNAs, we analysed the profiles of archived normal breast epithelium, LCIS lesions found alone, LCIS lesions concurrent with ILC, and the concurrent ILCs as a model of linear histological progression towards ILC. We identified two sets of differentially expressed miRNAs, the first set highly expressed in normal epithelium, including hsa-miR-224, -139, -10b, -450, 140, and -365, and the second set up-regulated during lobular neoplasia progression, including hsa-miR-375, -203, -425-5p, -183, -565, and -182. Using quantitative RT-PCR, we validated a trend of increasing expression for hsa-miR-375, hsa-miR-182, and hsa-miR-183 correlating with ILC progression. As we detected increased expression of hsa-miR-375 in LCIS lesions synchronous with ILC, we sought to determine whether hsa-miR-375 might induce phenotypes reminiscent of lobular neoplasia by expressing it in the MCF-10A 3D culture model of mammary acinar morphogenesis. Increased expression of hsa-miR-375 resulted in loss of cellular organization and acquisition of a hyperplastic phenotype. These data suggest that dysregulated miRNA expression contributes to lobular neoplastic progression.

Procurement of Human Tissues for Research Banking in the Surgical Pathology Laboratory: Prioritization Practices at Washington University Medical Center

Academic hospitals and medical schools with research tissue repositories often derive many of their internal human specimen acquisitions from their site's surgical pathology service. Typically, such acquisitions come from appropriately consented tissue discards sampled from surgical resections. Because the practice of surgical pathology has patient care as its primary mission, competing needs for tissue inevitably arise, with the requirement to preserve adequate tissue for clinical diagnosis being paramount. A set of best-practice gross pathology guidelines are summarized here, focused on the decision for tissue banking at the time specimens are macroscopically evaluated. These reflect our collective experience at Washington University School of Medicine, and are written from the point of view of our site biorepository. The involvement of trained pathology personnel in such procurements is very important. These guidelines reflect both good surgical pathology practice (including the pathologic features characteristic of various anatomic sites) and the typical objectives of research biorepositories. The guidelines should be helpful to tissue bank directors, and others charged with the procurement of tissues for general research purposes. We believe that appreciation of these principles will facilitate the partnership between surgical pathologists and biorepository directors, and promote both good patient care and strategic, value-added banking procurements.

mRNA and microRNA expression profiles in circulating tumor cells and primary tumors of metastatic breast cancer patients

PURPOSE

Molecular characterization of circulating tumor cells (CTC) holds great promise. Unfortunately, routinely isolated CTC fractions currently still contain contaminating leukocytes, which makes CTC-specific molecular characterization extremely challenging. In this study, we determined mRNA and microRNA (miRNA) expression of potentially CTC-specific genes that are considered to be clinically relevant in breast cancer.

EXPERIMENTAL DESIGN

CTCs were isolated with the epithelial cell adhesion molecule-based CellSearch Profile Kit. Selected genes were measured by real-time reverse transcriptase PCR in CTCs of 50 metastatic breast cancer patients collected before starting first-line systemic therapy in blood from 53 healthy blood donors (HBD) and in primary tumors of 8 of the patients. The molecular profiles were associated with CTC counts and clinical parameters and compared with the profiles generated from the corresponding primary tumors.

RESULTS

We identified 55 mRNAs and 10 miRNAs more abundantly expressed in samples from 32 patients with at least 5 CTCs in 7.5 mL of blood compared with samples from 9 patients without detectable CTCs and HBDs. Clustering analysis resulted in 4 different patient clusters characterized by 5 distinct gene clusters. Twice the number of patients from cluster 2 to 4 had developed both visceral and nonvisceral metastases. Comparing transcript levels in CTCs with those measured in corresponding primary tumors showed clinically relevant discrepancies in estrogen receptor and HER2 levels.

CONCLUSIONS

Our study shows that molecular profiling of low numbers of CTCs in a high background of leukocytes is feasible and shows promise for further studies on the clinical relevance of molecular characterization of CTCs.