Lobular neoplasia: frequency and association with other breast lesions

Are Columnar Cell Lesions the Earliest Non-Obligate Precursor in the Low-Grade Breast Neoplasia Pathway?

Columnar cell lesions (CCLs) of the breast comprise a spectrum of morphologic alterations of the terminal duct lobular unit involving variably dilated and enlarged acini lined by columnar epithelial cells. The World Health Organization currently classifies CCLs without atypia as columnar cell change (CCC) and columnar cell hyperplasia (CCH), whereas flat epithelial atypia (FEA) is a unifying term encompassing both CCC and CCH with cytologic atypia. CCLs have been increasingly recognized in stereotactic core needle biopsies (CNBs) performed for the assessment of calcifications. CCLs are believed to represent the earliest non-obligate precursor of low-grade invasive breast carcinomas as they share molecular alterations and often coexist with entities in the low-grade breast neoplasia pathway. Despite this association, however, the risk of progression of CCLs to invasive breast carcinoma appears low and may not exceed that of concurrent proliferative lesions. As the reported upgrade rates of pure CCL/FEA when identified as the most advanced high-risk lesion on CNB vary widely, the management of FEA diagnosed on CNB remains controversial. This review will include a historical overview of CCLs and will examine histologic diagnostic criteria, molecular alterations, prognosis and issues related to upgrade rates and clinical management.

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.

Analysis of gene copy number alterations by multiplex ligation-dependent probe amplification in columnar cell lesions of the breast

BACKGROUND

Columnar cell lesions (CCLs) are possible precursors of breast cancer, but little is known about the role of breast cancer-related genes in the progression of CCL to invasive breast cancer.

METHODS

Gene copy numbers of 17 breast cancer-related genes were analyzed using Multiplex Ligation-dependent Probe Amplification (MLPA) in CCL (N = 28), ductal carcinoma in situ (DCIS) grade I likely originating from CCL (N = 5), and paired CCL (N = 14/28) with DCIS (N = 7) and/or invasive carcinoma (N = 13). The genes included were BIRC5, C11orf30, CCND1, CCNE1, CDH1, CPD, EGFR, ERBB2, ESR1, FGFR1, IKBKB, MAPT, MED1, MTDH, MYC, TOP2A and TRAF4.

RESULTS

No high level gene amplifications were observed in CCL, but copy number gains were encountered for the C11orf30 (3/28), MYC, CPD, MTDH (2/28), and CCND1, CCNE1, ESR1 and TOP2A genes (1/28). In addition, CDH1 showed loss in 2/28 and TOP2A in 1/28 cases. CCLs with or without atypia exhibited comparable numbers of copy number changes (p = 0.312). Overall, the frequency of gene copy number changes increased from CCL towards DCIS and invasive carcinoma (p = 0.004). Also in the cases with synchronous lesions, the CCLs exhibited fewer copy number changes than the DCIS/invasive carcinomas.

CONCLUSIONS

CCLs carry copy number changes of several known breast cancer-related genes, thereby substantiating their role in breast carcinogenesis. Among them, CCND1 and ESR1 copy number gains and CDH1 copy number losses are of particular interest. Since the copy number changes observed were more prevalent in DCIS and invasive carcinoma than in CCL, the corresponding gene alterations may represent rather late occurring events in low nuclear grade breast carcinogenesis.

Usefulness and limitations of E-cadherin and β-catenin in the classification of breast carcinomas in situ with mixed pattern

Background

The distinction between lobular neoplasia of the breast and ductal carcinoma in situ has important therapeutic implications. In some cases, it is very difficult to determine whether the morphology of the lesion is ductal or lobular. The aim of this study was to evaluate the value of E-cadherin and β-catenin expression through the immunophenotypical characterization of carcinoma in situ with mixed pattern (CISM).

Methods

A total of 25 cases of CISM were analyzed considering cytology/mixed architecture (ductal and lobular), nuclear pleomorphism, loss of cell cohesion, and presence of comedonecrosis. The immunophenotype pattern was considered E-cadherin positive and β-catenin positive, or negative.

Results

Nineteen (76%) cases presented a mixed cytology and / or architectural pattern, two (8%) presented nuclear pleomorphism, two (8%) presented mixed cytology and nuclear pleomorphism, and two (8%) presented comedonecrosis and nuclear pleomorphism. A complete positivity for E-cadherin and β-catenin was observed in 11 cases (44%). In one case, the lesion was negative for both markers and showed nuclear pleomorphis. Thirteen lesions showed negative staining in areas of lobular cytology and positive staining in cells presenting the ductal pattern.

Conclusions

The expression of E-cadherin and β-catenin, combined with cytological and architectural analysis, may highlight different immunophenotypes and improve classification of CISM.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1693384202970681

Luminal B tumors are the most frequent molecular subtype in breast cancer of North African women: an immunohistochemical profile study from Morocco

Background

Breast cancer may be classified into luminal A, luminal B, HER2+/ER-, basal-like and normal-like subtypes based on gene expression profiling or immunohistochemical (IHC) characteristics. The aim of our study is to show the molecular profile characteristic of breast cancer in the North African population of Morocco. This work showed preliminary results and correlations with clinicopathological and histological parameters. Three hundred and ninety primary breast carcinomas tumor tissues were immunostained for ER, PR, HER2, CK5/6, CK8/18 and Ki67 using paraffin tissue.

Methods

We reviewed 390 cases of breast cancer diagnosed on January 2008 to December 2011 at the Department of pathology, Hassan II teaching hospital, Fez, Morocco. Age, size tumor, metastatic profile, node involvement profile, histological type and immunohistochemical profile were studied.

Results

The average age was 46 years; our patients were diagnosed late with a high average tumor size. Luminal B subtype was more prevalent (41.8%), followed by luminal A (30.5%), basal-like (13, 6%), Her2-overexpressing (9, 2%), and unclassified subtype (4.9%).

Conclusion

This study showed that molecular classification and biological profile may be different according to geographical distribution, to encourage further studies to know the genomic profile of tumors and the environment.

Virtual slide

http://www.diagnosticpathology.diagnomx.eu/vs/1675272504826544