Pitfalls in breast pathology

Accurate pathological diagnosis is the cornerstone of optimal clinical management for patients with breast disease. As non-operative diagnosis has now become the standard of care, histopathologists encounter the daily challenge of making definitive diagnoses on limited breast core needle biopsy (CNB) material. CNB samples are carefully evaluated using microscopic examination of haematoxylin and eosin (H&E)-stained slides and supportive immunohistochemistry (IHC), providing the necessary information to inform the next steps in the patient care pathway. Some entities may be difficult to distinguish on small tissue samples, and if there is uncertainty a diagnostic excision biopsy should be recommended. This review discusses (1) benign breast lesions that may mimic malignancy, (2) malignant conditions that may be misinterpreted as benign, (3) malignant conditions that may be incorrectly diagnosed as primary breast carcinoma, and (4) some IHC pitfalls. The aim of the review is to raise awareness of potential pitfalls in the interpretation of breast lesions that may lead to underdiagnosis, overdiagnosis, or incorrect classification of malignancy with potential adverse outcomes for individual patients.

The Chaperone System in Breast Cancer: Roles and Therapeutic Prospects of the Molecular Chaperones Hsp27, Hsp60, Hsp70, and Hsp90

Breast cancer (BC) is a major public health problem, with key pieces of information needed for developing preventive and curative measures still missing. For example, the participation of the chaperone system (CS) in carcinogenesis and anti-cancer responses is poorly understood, although it can be predicted to be a crucial factor in these mechanisms. The chief components of the CS are the molecular chaperones, and here we discuss four of them, Hsp27, Hsp60, Hsp70, and Hsp90, focusing on their pro-carcinogenic roles in BC and potential for developing anti-BC therapies. These chaperones can be targets of negative chaperonotherapy, namely the elimination/blocking/inhibition of the chaperone(s) functioning in favor of BC, using, for instance, Hsp inhibitors. The chaperones can also be employed in immunotherapy against BC as adjuvants, together with BC antigens. Extracellular vesicles (EVs) in BC diagnosis and management are also briefly discussed, considering their potential as easily accessible carriers of biomarkers and as shippers of anti-cancer agents amenable to manipulation and controlled delivery. The data surveyed from many laboratories reveal that, to enhance the understanding of the role of the CS in BS pathogenesis, one must consider the CS as a physiological system, encompassing diverse members throughout the body and interacting with the ubiquitin–proteasome system, the chaperone-mediated autophagy machinery, and the immune system (IS). An integrated view of the CS, including its functional partners and considering its highly dynamic nature with EVs transporting CS components to reach all the cell compartments in which they are needed, opens as yet unexplored pathways leading to carcinogenesis that are amenable to interference by anti-cancer treatments centered on CS components, such as the molecular chaperones.

PIK3CA-AKT pathway predominantly acts in developing ipsilateral breast tumor recurrence long after breast-conserving surgery

PURPOSE

Ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy is seen after a long interval, but the clinical classification of Residual Tumor Recurrence (RR) or Double Primary (DP) needs to be validated. We used genome profiling to identify the genetic alterations associated with IBTR.

METHODS

Among 1881 breast cancer patients treated with breast-conserving therapy between 1999 and 2018, IBTR occurred in 52 patients (2.8%). Of these 22 patients who consented for genomic analysis of Primary Breast Cancer (T1) and IBTR (T2) were studied. When the same gene mutations in T1 and T2 were identified, it was classified as genomic residual recurrence gRR, and when no shared mutations identified, it was classified as gDP. The differences between clinical and genomic classification were compared. Furthermore, the pathway of the genes which were responsible for recurrence was also examined.

RESULTS

Of 13 clinically diagnosed RRs (cRRs), 11 were gRR and 2 were gDPs, while of 9 cDPs, 6 were gDP and 3 gRR, with a match rate of 17/22 (77%). We searched for genes involved in IBTR: PIK3CA-AKT pathway mutations were found in 12 of 14 gRRs (86%) in T1, and only 2 of 8 gDPs (25%) with significant difference (p = 0.004). When both of PBC and IBTR compared, PIK3CA-AKT pathway abnormalities were 24/28 (86%) in the gRR and 5/16 (31%) in the gDP (p < 0.001).

CONCLUSIONS

Genome profiling revealed that abnormalities in the PIK3CA-AKT pathway in long-term residential recurrences and are a crucial molecular group in the development of IBTR.

Prognostic Significance of Lobular Carcinoma In-Situ (LCIS) Diagnosed Alongside Invasive Breast Cancer

Purpose:

Women with lobular carcinoma in-situ (LCIS) have an increased risk for developing breast cancer (BC) compared with the general population. However, little is known about the clinical implication of diagnosing LCIS concurrently with an invasive breast cancer. We aimed to define the rate of LCIS diagnosed concurrently with an invasive breast cancer and investigate the risk of contralateral breast cancer (CBC) during survivorship care.

Materials and methods:

A single center retrospective review over 6 years identified women with stage I-III BC who underwent lumpectomy or unilateral mastectomy. Patients with or without concurrent LCIS were compared using Chi-squared analyses to assess for differences in clinicopathologic factors and risk of future CBC (including invasive and in-situ disease).

Results:

Of 1808 patients, 16.6% (n = 301) had LCIS concurrent with their index breast cancer. Patients with LCIS had a higher rate of subsequent CBC development than those without LCIS (3.3% versus 1.0%, P = .004). The risk ratio for patients with LCIS developing subsequent CBC compared with those without LCIS was 3.3 (95% confidence interval [CI]: 1.5-7.3).

Conclusions:

Patients with LCIS diagnosed concurrently with their index breast cancer at surgery are at higher risk for subsequent CBC than those without LCIS. The evidence from this study suggest that it may be appropriate for women with LCIS diagnosed alongside an index breast cancer to consider on-going high-risk screening during survivorship care.

Trends in incidence, treatment, survival and subsequent breast cancer in lobular carcinoma in situ in the Netherlands: A population-based analysis

Purpose

We analysed incidence, treatment, survival, occurrence of ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC) after lobular carcinoma in situ (LCIS) in the Netherlands.

Methods

All women diagnosed with classic LCIS between 1989 and 2017 were identified from the Netherlands Cancer Registry. We calculated overall (OS), relative survival (RS) and cumulative incidence functions (CIF, accounting for competing risks) of mortality, DCIS and IBC. For IBC, standardised incidence ratios (SIR) of IBC were calculated. Analyses were stratified for surgical treatment.

Results

We included 1890 patients. Median age was 51 years. Median follow-up was 8.5 years. In 1989–2017, LCIS incidence increased from 41 to 124, surgical treatment decreased from 100% to 41.1 % – mostly BCS. 10-year OS and 20-year RS exceeded 90 % in all subgroups. Overall, 48 (2.5 %) and 270 (14.3 %) patients were diagnosed with DCIS and IBC. IBCs were mostly early-stage. After mastectomy, 13 of 14 IBCs presented contralaterally. In the other groups, 64.8–70.9 % of IBCs presented ipsilaterally, 34.5–53.9 % of these were lobular. The SIR of ipsilateral IBC was highest after no surgery (6.9, 95%CI:4.9–9.4), lowest after mastectomy (0.2, 95%CI:0.4–0.8).

Conclusion

LCIS incidence increased, surgical treatment decreased. The low mortality risks support consideration of active surveillance. However, the increased IBC incidence suggests careful monitoring.

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The incidence of LCIS increased, while surgical treatment decreased over time.

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10- and 20-year relative survival rates exceeded 90 %, irrespective of surgery.

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The risk of breast cancer was highest after no surgery, lowest after mastectomy.

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Subsequent breast cancers were generally of low stage.

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Active surveillance for LCIS is advised, with the current follow-up five years.

High-risk lesions of the breast: concurrent diagnostic tools and management recommendations

Breast lesions with uncertain malignant behavior, also known as high-risk or B3 lesions, are composed of a variety of pathologies with differing risks of associated malignancy. While open excision was previously preferred to manage all high-risk lesions, tailored management has been increasingly favored to reduce overtreatment and spare patients from unnecessary anxiety or high healthcare costs associated with surgical excision. The purpose of this work is to provide the reader with an accurate overview focused on the main high-risk lesions of the breast: atypical intraductal epithelial proliferation (atypical ductal hyperplasia), lobular neoplasia (including the subcategories lobular carcinoma in situ and atypical lobular hyperplasia), flat epithelial atypia, radial scar and papillary lesions, and phyllodes tumor. Beyond merely presenting the radiological aspects of these lesions and the recent literature, information about their potential upgrade rates is discussed in order to provide a useful guide for appropriate clinical management while avoiding the risks of unnecessary surgical intervention (overtreatment).

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.

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.

Management of High-Risk Breast Lesions

High-risk breast lesions (HRLs) are a group of heterogeneous lesions that can be associated with a synchronous or adjacent breast cancer and that confer an elevated lifetime risk of breast cancer. Management of HRLs after core needle biopsy may include close imaging and clinical follow-up or excisional biopsy to evaluate for cancer. This article reviews histologic features and clinical presentation of each of the HRLs, current evidence with regard to management, and guidelines from the American Society of Breast Surgeons and National Comprehensive Cancer Network. In addition, imaging surveillance and risk-reduction strategies for women with HRLs are discussed.

Triple-Negative Breast Cancer Comparison With Canine Mammary Tumors From Light Microscopy to Molecular Pathology

Many similar characteristics in human and dog cancers including, spontaneous development, clinical presentation, tumor heterogeneity, disease progression, and response to standard therapies have promoted the approval of this comparative model as an alternative to mice. Breast cancer represents the second most frequent neoplasm in humans after lung cancer. Triple-negative breast cancers (TNBC) constitute around 15% of all cases of breast cancer and do not express estrogen receptor (ER), progesterone receptor (PR), and do not overexpress human epidermal growth factor receptor 2 (HER2). As a result, they do not benefit from hormonal or trastuzumab-based therapy. Patients with TNBC have worse overall survival than patients with non-TNBC. Lehmann and collaborators described six different molecular subtypes of TNBC which further demonstrated its transcriptional heterogeneity. This six TNBC subtype classification has therapeutic implications. Breast cancer is the second most frequent neoplasm in sexually intact female dogs after skin cancer. Canine mammary tumors are a naturally occurring heterogeneous group of cancers that have several features in common with human breast cancer (HBC). These similarities include etiology, signaling pathway activation, and histological classification. Molecularly CMTs are more like TNBCs, and therefore dogs are powerful spontaneous models of cancer to test new therapeutic approaches, particularly for human TNBCs. More malignant tumors of the breast are more often ER and PR negative in both humans and dogs. Promising breast cancer biomarkers in both humans and canines are cancer-associated stroma (CAS), circulating tumor cells and tumor DNA (ctDNA), exosomes and miRNAs, and metabolites.

[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.

Pitfalls and controversies in pathology impacting breast cancer management

Introduction: Breast cancer is a heterogeneous disease, at morphological, molecular, and clinical levels and this has significant implications for the diagnosis and management of the disease. The introduction of breast screening, and the use of small tissue sampling for diagnosis, the recognition of new morphological and molecular subtypes, and the increasing use of neoadjuvant therapies have created challenges in pathological diagnosis and classification.Areas covered: Areas of potential difficulty include columnar cell lesions, particularly flat epithelial atypia, atypical ductal hyperplasia, lobular neoplasia and its variants, and a range of papillary lesions. Fibroepithelial, sclerosing, mucinous, and apocrine lesions are also considered. Established and newer prognostic and predictive markers, such as immune infiltrates, PD-1 and PD-L1 and gene expression assays are evaluated. The unique challenges of pathology assessment post-neoadjuvant systemic therapy are also explored.Expert opinion: Controversies in clinical management arise due to incomplete and sometimes conflicting data on clinicopathological associations, prognosis, and outcome. The review will address some of these challenges.

Benign breast papillary lesions diagnosed on core biopsy: upgrade rate and risk factors associated with malignancy on surgical excision

Evaluation of radiologically detected breast lesions is a common task in surgical pathology. Some benign lesions on biopsy are associated with an upgrade to in situ or invasive carcinoma on excision. The non-atypical breast papilloma has published upgrade rates of 0 to 29%. Traditionally, papillomas have been managed surgically, but the wide range of upgrade rates has raised uncertainty about the need for routine surgical excision. This study aims to identify risk factors associated with upgrade and determine the upgrade rate of non-atypical papillomas at our institution. In a retrospective review of pathology reports, we identified 266 patients with a diagnosis of benign papilloma on breast core biopsy. One hundred eighty-two patients underwent surgical resection. The final surgical pathology reports of all patients were reviewed and divided into one of two groups-benign or malignant. Twenty-one patients had a final diagnosis of in situ or invasive carcinoma, resulting in an upgrade rate of 12%. Radiologically detected lesions with calcifications were at higher risk for upgrade (OR = 4.45, 95% CI 1.08-18.27) than lesions without calcifications. Additionally, advanced patient age (OR = 1.07, 95% CI 1.03-1.13) and lesion size greater than 0.5 cm (OR = 2.59, 95% CI 0.38-17.48) was associated with upgrade to malignancy. Routine surgical excision of all papillomas is not recommended. Younger patients without high-risk features may benefit from clinical and radiologic follow-up alone. Accurate risk stratification will spare low-risk women unnecessary surgery.

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.

The comprehensive role of E-cadherin in maintaining prostatic epithelial integrity during oncogenic transformation and tumor progression

E-cadherin complexes with the actin cytoskeleton via cytoplasmic catenins and maintains the functional characteristics and integrity of the epithelia in normal epithelial tissues. Lost expression of E-cadherin disrupts this complex resulting in loss of cell polarity, epithelial denudation and increased epithelial permeability in a variety of tissues. Decreased expression of E-cadherin has also been observed in invasive and metastatic human tumors. In this study, we investigated the effect of E-cadherin loss in prostatic epithelium using newly developed genetically engineered mouse models. Deletion of E-cadherin in prostatic luminal epithelial cells with modified probasin promoter driven Cre (PB-Cre4) induced the development of mouse prostatic intraepithelial neoplasia (PIN). An increase in levels of cytoplasmic and nuclear β-catenin appeared in E-cadherin deleted atypical cells within PIN lesions. Using various experimental approaches, we further demonstrated that the knockdown of E-cadherin expression elevated free cytoplasmic and nuclear β-catenin and enhanced androgen-induced transcription and cell growth. Intriguingly, pathological changes representing prostatic epithelial cell denudation and increased apoptosis accompanied the above PIN lesions. The essential role of E-cadherin in maintaining prostatic epithelial integrity and organization was further demonstrated using organoid culture approaches. To directly assess the role of loss of E-cadherin in prostate tumor progression, we generated a new mouse model with bigenic Cdh1 and Pten deletion in prostate epithelium. Early onset, aggressive tumor phenotypes presented in the compound mice. Strikingly, goblet cell metaplasia was observed, intermixed within prostatic tumor lesions of the compound mice. This study provides multiple lines of novel evidence demonstrating a comprehensive role of E-cadherin in maintaining epithelial integrity during the course of prostate oncogenic transformation, tumor initiation and progression.

The biological significance of E-cadherin in maintaining prostatic epithelial integrity and related molecular mechanisms are still unclear. In this study, using mouse genetic tools, we directly address this important and unresolved question. Conditional deletion of E-cadherin in mouse prostatic epithelia resulted in prostatic intraepithelial neoplasia (PIN) development but no prostatic tumor formation. Both in vivo and in vitro data showed that loss of E-cadherin modulates the cellular localization of β-catenin, elevates its cytoplasmic and nuclear levels, and enhances its activity in transcription and cell proliferation. Intriguingly, in addition to PIN lesions, increased epithelial denudation and cell apoptosis also appeared within PIN lesions. This implicates that although lost E-cadherin is sufficient to introduce oncogenic transformation in prostatic epithelia, it also induces cell apoptosis and disrupts epithelial structure, preventing atypical PIN cells from progressing to tumor cells. Simultaneous deletion of Pten, a tumor suppressor, and E-cadherin in prostatic epithelia resulted in early onset, invasive prostatic tumors with admixture of goblet cells. These results demonstrate a critical role of E-cadherin in promoting prostatic tumor transdifferentiation and progression. This study further elucidates the dynamic role of E-cadherin in maintaining prostatic epithelial integrity during tumor initiation and progression.

Immunohistochemistry for diagnosis and prognosis of breast cancer: a review

Breast cancer is the most prevalent malignant tumor and main oncologic cause of mortality in women. Although most diagnosis of breast pathology is accomplished using hematoxylin and eosin stained sections, some cases require immunohistochemistry for proper evaluation. We investigated the latter cases including distinctions between ductal and lobular carcinoma, in situ and invasive carcinoma, typical ductal hyperplasia and atypical ductal hyperplasia/ductal carcinoma in situ, papillary and spindle cell lesion assessment, metastasis evaluation, and assessment of prognostic and therapy markers. E-cadherin is used to differentiate ductal and lobular carcinoma; 34βE12, CK8, p120 catenin and β-catenin also produce consistent results. Myoepithelial cell (MEC) stains are used to evaluate in situ and invasive carcinoma; calponin, smooth muscle myosin heavy chain and p63 are sensitive/specific markers. 34βE12 and CK5/6 are positive in ductal hyperplasia, which enables its differentiation from atypical ductal hyperplasia and ductal carcinoma in situ. CK 5/6, ER and MEC markers are consistent options for evaluating papillary lesions. Spindle cell lesions can be assessed using β-catenin, SMA, CD34, p63, CKs and hormone receptors. It is important to differentiate primary carcinomas from metastases; the most commonly used markers to identify breast origin include mammaglobin, GCDFP-15, GATA3 and ER, although none of these is completely sensitive or specific. Immunohistochemistry can be used to evaluate central prognostic and predictive factors including molecular subtypes, HER2, hormone receptors, proliferation markers (Ki-67) and lymph-vascular invasion markers including ERG, CD31, CD34, factor VIII and podoplanin. Owing to the complexity of mammary lesions, diagnosis also depends on each particular situation, evaluation of cytological characteristics revealed by immunochemistry and correlation with histological findings.

Pre-operative management of Pleomorphic and florid lobular carcinoma in situ of the breast: Report of a large multi-institutional series and review of the literature

BACKGROUND

Pleomorphic and Florid Lobular carcinoma in situ (P/F LCIS) are rare variants of LCIS, the exact nature of which is still debated.

AIM

To collect a large series of P/F LCIS diagnosed on preoperative biopsies and evaluate their association with invasive carcinoma and high grade duct carcinoma in situ (DCIS). Data obtained were compared with those reported in the literature.

METHODS

A multi-institutional series of P/F LCIS was retrieved. All cases were diagnosed on pre-operative biopsies, which was followed by an open surgical excision. Data on post-operative histopathology were available. A literature review was performed.

RESULTS

A total of 117 cases were collected; invasive carcinoma and/or DCIS was present in 78/117 cases (66.7%). Seventy cases of P/F LCIS were pure on biopsy and 31 of these showed pathological upgrade in post-surgical specimens. Pre-operative biopsy accuracy was 47/78 (60.3%); pre-operative biopsy underestimation of cancer was 31/78 (39,7.%). In the literature review papers, invasive carcinoma or DCIS was associated with 274 of 418 (65.5%) cases of P/F LCIS. Pre-operative biopsy accuracy was 66% (181/274) whereas pre-operative biopsy underestimation of cancer was 33.9% (93/274).

CONCLUSIONS

The data presented here indicate that P/F LCIS is frequently associated with invasive carcinoma or high grade DCIS and that pre-operative biopsy is associated with an underestimation of malignancy. Open surgery is indicated when P/F LCIS is diagnosed pre-operatively.

Multidisciplinary management of CDH1 germinal mutation and prophylactic management hereditary lobular breast cancer: A case report

INTRODUCTION

Germline CDH1 mutations, classically associated with hereditary diffuse gastric cancer (HDGC), also imply an increased lifetime risk of developing lobular breast cancer (LBC) in a highly penetrant autosomal dominant manner.

PRESENTATION OF CASE

We report a 44-year-old woman CDH1 mutation carrier with a strong family history of cancer, who previously had prophylactic total gastrectomy. We registered normal findings at the breast and axilla assessment. Mammography, ultrasonography and breast MRI scans were negative for cancer. In our Institute a bilateral prophylactic mastectomy followed by breast reconstruction was performed. Foci of atypical lobular hyperplasia(ALH) and lobular carcinoma in situ (LCIS) were histologically shown.

DISCUSSION

The current consensus guidelines for women with pathogenic CDH1 mutations recommend annual mammography, ultrasound, breast MRI scans and clinical breast examination starting at the age of 35. Due to the well-documented aggressive behavior of this particular type of cancer, bilateral mastectomy and reconstruction would be more beneficial for this kind of high-risk patients.

CONCLUSION

Conflicting evidences and lacking data about the benefits in terms of overall survival, disease-free survival and the long-term outcomes related to prophylactic bilateral mastectomy for CDH1 mutation carriers restrict the instruction for this type of procedure to selected cases, which should always be managed by a multidisciplinary team.

Validation of the IBIS breast cancer risk evaluator for women with lobular carcinoma in-situ

BACKGROUND

Management advice for women with lobular carcinoma in situ (LCIS) is hampered by the lack of accurate personalised risk estimates for subsequent invasive breast cancer (BC). Prospective validation of the only tool that estimates individual BC risk for a woman with LCIS, the International Breast Cancer Intervention Study Risk Evaluation Tool (IBIS-RET), is lacking.

METHODS

Using population-based cancer registry data for 732 women with LCIS, the calibration and discrimination accuracy of IBIS-RET Version 7.2 were assessed.

RESULTS

The mean observed 10-year risk of invasive BC was 14.1% (95% CI:11.3%-17.5%). IBIS-RET overestimated invasive BC risk (p = 0.0003) and demonstrated poor discriminatory accuracy (AUC 0.54, 95% CI: 0.48 - 0.62).

CONCLUSIONS

Clinicians should understand that IBIS-RET Version 7.2 may overestimate 10-year invasive BC risk for Australian women with LCIS. The newer IBIS-RET Version 8.0, released September 2017, includes mammographic density and may perform better, but validation is needed.

Hereditary lobular breast cancer with an emphasis on E-cadherin genetic defect

Recent studies have reported germline CDH1 mutations in cases of lobular breast cancer (LBC) not associated with the classical hereditary diffuse gastric cancer syndrome. A multidisciplinary workgroup discussed genetic susceptibility, pathophysiology and clinical management of hereditary LBC (HLBC). The team has established the clinical criteria for CDH1 screening and results' interpretation, and created consensus guidelines regarding genetic counselling, breast surveillance and imaging techniques, clinicopathological findings, psychological and decisional support, as well as prophylactic surgery and plastic reconstruction. Based on a review of current evidence for the identification of HLBC cases/families, CDH1 genetic testing is recommended in patients fulfilling the following criteria: (A) bilateral LBC with or without family history of LBC, with age at onset <50 years, and (B) unilateral LBC with family history of LBC, with age at onset <45 years. In CDH1 asymptomatic mutant carriers, breast surveillance with clinical examination, yearly mammography, contrast-enhanced breast MRI and breast ultrasonography (US) with 6-month interval between the US and the MRI should be implemented as a first approach. In selected cases with personal history, family history of LBC and CDH1 mutations, prophylactic mastectomy could be discussed with an integrative group of clinical experts. Psychodecisional support also plays a pivotal role in the management of individuals with or without CDH1 germline alterations. Ultimately, the definition of a specific protocol for CDH1 genetic screening and ongoing coordinated management of patients with HLBC is crucial for the effective surveillance and early detection of LBC.

A unique case of total metastatic lobular breast carcinoma, originating from diffused microcalcifications, presented in a postmenopausal woman, without clinical manifestations

INTRODUCTION

Lobular breast carcinoma includes lobular carcinoma in situ (LCIS) and invasive lobular carcinoma (ILC). The association of LCIS with total metastatic lobular breast cancer is very rare.

PRESENTATION OF CASE

We present a case of a totally metastatic lobular breast cancer in an asymptomatic 64-year-old postmenopausal woman, with no suspicious microcalcifications in mammography. A total hysterectomy with bilateral salpingo-oophorectomy, pelvic lymphadenectomy, infracolic omentectomy and appendectomy was performed along with a quadrantectomy of the upper outer quadrant of left breast, and systematic isolateral lymphadenectomy of the left axilla.

DISCUSSION

LCIS is usually undetectable because it isn't associated with clinical abnormalities in clinical examination and is presented in mammography as microcalcifications or focal asymmetric densities. ILC histopathologic features are responsible for the high false-negative rates on mammography, leading to moderate detection sensitivity.

CONCLUSION

Our case is a very rare condition. No 'similar' case have been described in the literature so far.