Lobular Carcinoma In Situ Research Articles

Pleomorphic Lobular Carcinoma In Situ Composed of Signet-Ring Cells Mimicking Ductal Carcinoma In Situ with A Papillary Pattern: A Case Report.

While some forms of invasive or in situ carcinoma of the breast may be partly composed of signet-ring cells, signet-ring cells rarely become a prominent feature of pleomorphic lobular carcinoma in situ (LCIS). We report a rare example of pleomorphic LCIS composed predominantly of signet-ring cells with a papillary pattern mimicking ductal carcinoma in situ (DCIS). A 58-year-old woman presented with a mass in the left breast detected by ultrasonography. Fourteen years previously, the patient underwent right breast-conserving surgery for invasive breast carcinoma of no special type. Ultrasonography revealed an irregular parallel, angular hypoechoic mass measuring 1.5 cm in the left breast. An ultrasound-guided core needle core biopsy was conducted. Microscopically, the lesion was composed of epithelial cells supported by a fibrovascular stroma. The majority (> 70%) of the lesional cells between the fibrovascular stalks showed signet-ring cell features. Some of the nuclei of the signet-ring cells showed intermediate-grade atypia. A mucicarmine stain showed intracytoplasmic mucin in the signet-ring cells. Immunohistochemistry for E-cadherin was negative in the tumor cells. After surgical excision, the final diagnosis was a pleomorphic LCIS. To our knowledge, there have been no previous reports of pleomorphic LCIS consisting primarily of signet-ring cells with a papillary pattern.

Use of web-based decision support to improve informed choice for chemoprevention: a qualitative analysis of pre-implementation interviews (SWOG S1904)

BackgroundWomen with high-risk breast lesions, such as atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS), have a 4- to tenfold increased risk of breast cancer compared to women with non-proliferative breast disease. Despite high-quality data supporting chemoprevention, uptake remains low. Interventions are needed to break down barriers.MethodsThe parent trial, MiCHOICE, is a cluster randomized controlled trial evaluating the effectiveness and implementation of patient and provider decision support tools to improve informed choice about chemoprevention among women with AH or LCIS. For this pre-implementation analysis, 25 providers participated in semi-structured interviews prior to accessing decision support tools. Interviews sought to understand attitudes/beliefs and barriers/facilitators to chemoprevention.ResultsInterviews with 25 providers (18 physicians and 7 advanced practice providers) were included. Providers were predominantly female (84%), white (72%), and non-Hispanic (88%). Nearly all providers (96%) had prescribed chemoprevention for eligible patients. Three themes emerged in qualitative analysis. The first theme describes providers’ confidence in chemoprevention and the utility of decision support tools. The second theme elucidates barriers to chemoprevention, including time constraints, risk communication and perceptions of patients’ fear of side effects and anxiety. The third theme is the need for early implementation of decision support tools.ConclusionsThis qualitative study suggests that providers were interested in the early inclusion of decision aids (DA) in their chemoprevention discussion workflow. The DAs may help overcome certain barriers which were elucidated in these interviews, including patient level concerns about side effects, clinic time constraints and difficulty communicating risk. A multi-faceted intervention with a DA as one active component may be needed.Trial registrationThis trial was registered with the NIH clinical trial registry, clinicaltrials.gov, NCT04496739.

Is the Number or Proximity of Margins Less than 2 mm Associated with an Increased Mastectomy Rate in Patients Attempting Breast Conservation Therapy for Ductal Carcinoma In Situ?

Consensus guidelines recommend ≥ 2 mm margins in patients undergoing partial mastectomy (PM) for ductal carcinoma in situ (DCIS). It is unknown whether the number or proximity of margins less than 2 mm is associated with an increased mastectomy rate in patients attempting breast conservation therapy (BCT) for DCIS. The aim of this study is to examine this relationship. An institutional database review identified 208 patients with DCIS who underwent PM at a tertiary referral center and community hospitals from July 2020 to June 2023. Patients with a history of breast cancer, previous surgery for breast cancer, ipsilateral invasive carcinoma, papillary carcinoma, Paget's disease, more lobular carcinoma in situ (LCIS) than DCIS present, initial mastectomy, no DCIS present, routine shave margins (of all vectors), and ≥ 2 mm margins of all six vectors were excluded. Selective intraoperative margin re-excisions were included. A total of 208 patients who met inclusion criteria were retrospectively reviewed. 122 (25%) had one close/positive (< 2 mm) margin and 86 (18%) had two or more close/positive margins. Of the patients with one close/positive margin, 7% (9/122) eventually underwent mastectomy. Of the patients with two or more close/positive margins, 20% (17/86) eventually underwent mastectomy. Overall, no patients with opposing margins underwent mastectomy. Patients undergoing PM for DCIS have a mastectomy rate that is increased threefold, with two or more close/positive margins at initial PM, when compared with those with only one close/positive margin. The presence of opposing close/positive margins at initial PM did not increase the mastectomy rate and most were cleared with re-excision.

Altered cytokeratin 5 expression in breast lobular myoepithelial cells

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

Making Informed Choices On Incorporating Chemoprevention into carE (MiCHOICE, SWOG 1904): Design and methods of a cluster randomized controlled trial

IntroductionWomen with atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS) have a significantly increased risk of breast cancer, which can be substantially reduced with antiestrogen therapy for chemoprevention. However, antiestrogen therapy for breast cancer risk reduction remains underutilized. Improving knowledge about breast cancer risk and chemoprevention among high-risk patients and their healthcare providers may enhance informed decision-making about this critical breast cancer risk reduction strategy. Methods/designWe are conducting a cluster randomized controlled trial to evaluate the effectiveness and implementation of patient and provider decision support tools to improve informed choice about chemoprevention among women with AH or LCIS. We have cluster randomized 26 sites across the U.S. through the SWOG Cancer Research Network. A total of 415 patients and 200 healthcare providers are being recruited. They are assigned to standard educational materials alone or combined with the web-based decision support tools. Patient-reported and clinical outcomes are assessed at baseline, after a follow-up visit at 6 months, and yearly for 5 years. The primary outcome is chemoprevention informed choice after the follow-up visit. Secondary endpoints include other patient-reported outcomes, such as chemoprevention knowledge, decision conflict and regret, and self-reported chemoprevention usage. Barriers and facilitators to implementing decision support into clinic workflow are assessed through patient and provider interviews at baseline and mid-implementation. Results/discussionWith this hybrid effectiveness/implementation study, we seek to evaluate if a multi-level intervention effectively promotes informed decision-making about chemoprevention and provide valuable insights on how the intervention is implemented in U.S. clinical settings. Trial RegistrationNCT04496739

Abstract PO4-28-09: Upregulation of the immune checkpoint protein B7-H3 is associated with an immune suppressive microenvironment in progression from in situ to invasive lobular breast cancer

Abstract Invasive lobular breast cancer (ILC) is an understudied subtype of breast cancer characterized by late recurrence, metastasis to serosal surfaces including the peritoneum, and poor long-term outcomes. Lobular carcinoma in situ (LCIS) is a non-obligate precursor to ILC but is associated with a 30% increased risk of developing ILC. Therefore, understanding the underlying changes that occur in the invasive lobular cells as well as their tumor microenvironment (TME) during the transition from LCIS to ILC is critical for the development of novel therapeutic targets that could be used in early disease. To address this, we used combined spatial whole genome transcriptomics and a 97-protein proteomics assay to examine the spatial molecular profiles of coexistent LCIS and ILC. PanCK-positive tumor cells and panCK-negative stromal cells were segmented and analyzed separately for both RNA and protein. Despite the close spatial proximity of LCIS and ILC, there were notable differences in gene and protein expression in the tumor cells as well as the tumor microenvironment (TME). RNA profiling revealed significant upregulation of genes encoding essential components of the extracellular matrix, including type I, 3 and 5 collagens, small leucine-rich proteoglycans byglycan (BGN) and lumican (LUM), periostin (POSTN) and secreted protein acidic and cysteine rich (SPARC). Metalloprotease genes MMP2 and MMP11 were also upregulated. Genes highly expressed in the LCIS tumor compartment were KRT5, KRT14 KRT17 and MYLK which are highly expressed in myoepithelial cells at the periphery of the LCIS. One of the most upregulated proteins in ILC cells was B7 homology 3 protein (B7-H3) or Cluster of Differentiation 276 (CD276). B7-H3 is a transmembrane immunoregulatory protein belonging to the B7 family (that also includes PD-L1 and PD-L2). This immune checkpoint protein is overexpressed in many tumors but is barely expressed in normal cells. B7-H3 has been associated with several aspects of cancer progression, such as evasion of tumor immune surveillance and metastasis, and is strongly linked to poor prognosis in cancer. Compared to the LCIS TME, B7-H3 was also the most upregulated protein in the ILC TME along with the tumor-promoting M1 macrophage marker CD68 and the regulatory T-cell marker FOXP3. The lymphocyte marker CD45 was downregulated as well as T-cell proteins CD3, CD40 and granzyme B. Moreover, CD27, a memory B-cell marker was most highly expressed in the TME surrounding LCIS compared to ILC. Overall, these molecular profiles support a transition to a toward a much more immunosuppressive environment for invasive tumor cells compared to LCIS. Based on these data, our working hypothesis is that upregulation of B7-H3 on lobular tumor cells promotes invasion allowing interaction with laminins, integrins and other ECM proteins in the basement membrane and the interstitial membrane as LCIS acquire invasive properties of ILC. Furthermore, upregulation of B7-H3 on CD3+ HLA-DR+ expressing antigen presenting cells also promotes a suppressive immune microenvironment by inhibiting T-cell proliferation and downregulating cytokine production. In sum, these strongly concurrent spatial transcriptome and protein data suggest that B7-H3 and the immune suppressive network of ILC may be a promising target for early stage lobular breast cancer. B7-H3 Inhibitors could be explored in the neoadjuvant setting to evaluate the efficacy of immunotherapy in primary ILC. Citation Format: Lynda Bennett, Sunati Sahoo, Cheryl Lewis, Indu Raman, Candace Frerich, Guanchun Chen, Min Xu, Suzanne Conzen. Upregulation of the immune checkpoint protein B7-H3 is associated with an immune suppressive microenvironment in progression from in situ to invasive lobular breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-28-09.

Abstract PO5-13-11: Quantitative Assessment of HER2 Expression in Intraductal Neoplasms of the Breast

Abstract HER2 (ERBB2) is an established prognostic and predictive marker for patients with invasive breast cancer and used in HER2-targeted therapy. The clinical and biological significance of expression of HER2 protein in patients with intraductal neoplasms of the breast is not well characterized. In this study, we used our HS-HER2 (High Sensitivity-HER2) which is a CAP/CLIA certified laboratory derived test (LDT) using quantitative immunofluorescence (QIF). We evaluated HER2 expression in DCIS (ductal carcinoma in situ), LCIS (lobular carcinoma in situ) and benign lesions to correlate with their clinicopathologic characteristics. Thirty- eight cases of DCIS, and fourteen cases of LCIS and thirty benign cases were selected from the Yale Pathology department archives and 252 ROIs (regions of interest) were annotated by a board-certified pathologist. DCIS is classified according to the three-tier nuclear grading system: low, intermediate, and high-nuclear grade. LCIS is classified as PLCIS (pleomorphic variant) and CLCIS (classic LCIS) according to the WHO classification of breast tumors. Serial sections of FFPE tumor specimens were used to accurately quantify the HER2 expression by the HS-HER2 assay and the acquisition by QuPath v.04 with Qymia extension. According to the LOD (limit of detection,3 amol/mm2), LOQ (limit of quantification, 9 amol/mm2) and LOL (limit of linearity, 23 amol/mm2) of the optimized HS-HER2 assay as performed in our CLIA lab shows a broad range of HER2 expression in both DCIS and LCIS lesions, ranging from 0.7 amol/mm2 to 111.4 amol/mm2 in DCIS and 3.6 amol/mm2 to 49.9 amol/mm2 in LCIS. High grade DCIS lesions express higher average HER2 levels (111.4 + 0.7 amol/mm2) than combined low and intermediate grade DCIS (77.9 +1.9 amol/mm2) with no significant difference between low/intermediate and high-grade DCIS. CLCIS lesions express higher average HER2 level (49.9 + 3.6 amol/mm2) than PLCIS (35.1 + 5.4amol/mm2) but again this is not statistically significant. HER protein expression is relatively low in benign lesions ranging from 0.8 to 8.4 amol/mm2. Using the HS-HER2 assay, our results show quantitative level HER2 levels in DCIS and LCIS breast lesions. These findings may be important as HER2 targeted therapies that work in gene-unamplified cancer (HER2 conjugated ADCs) gain broader usage in the clinic. Citation Format: Nay Nwe Nyein Chan, Haiying Zhan, Revekka Khaimova, Thazin Aung, Charles Robbins, Patricia Gaule, David Rimm. Quantitative Assessment of HER2 Expression in Intraductal Neoplasms of the Breast [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-13-11.

Abstract ED02-02: The Challenges of Lobular Carcinoma

Abstract Infiltrating lobular carcinoma (ILC) and lobular carcinoma in situ (LCIS) were first described in the1940s by two Memorial Hospital pathologists, Foote and Stewart. They were most intrigued by the infiltrative appearance of these lobular cancers which they described as demonstrating large numbers of isolated, loose or dyscohesive cells of rather uniform size but of varying shape. We now recognize that this dyscohesive growth pattern is the result of loss of a functional e-cadherin protein; a distinguishing feature between ILC and invasive ductal carcinoma (IDC). Several studies comparing clinical features and outcomes between ILC and IDC have generated consistent findings. Lobular cancers are more likely to be ER+, larger, lower grade, less likely to be detected on MMG and more likely to have positive margins at breast conserving surgery (BCS), or to require mastectomy. Yet importantly, if BCS is successful, local recurrence and rates of contralateral breast cancer are equal for ILC and IDC. Although lobular cancers represents only 5-15% of all breast cancer, numerically, if ILC was an independent cancer in women, it would rank as the 6th most common cancer in women. Notably the incidence of ILC rose sharply in the late 80s throughout the 90s, and it has become clear that there is a strong relationship between ILC and hormone replacement therapy. Perhaps the “strongest” risk factor for ILC, is LCIS. Classic LCIS is an incidental finding – there are no pathnogmonic features on breast imaging or gross examination of tissue. On microscopic examination it is often multicentric and bilateral. Although originally considered a precursor to ILC and treated with mastectomy, over the years it was realized that rates of ipsilateral cancer in women who were not treated for LCIS were lower than expected and were quite similar to rates of contralateral breast cancer – and this combined with the fact that only 50% of the cancers were of the lobular phenotype led to a movement to consider LCIS as a high risk lesion. Contemporary data continue to support this management approach as rates of cancer development in women with a diagnosis of LCIS are consistently reported at 1-2% per year and the risk is conferred bilaterally, with a slightly higher representation of ILC in the ipsilateral breast. In this presentation we will review areas of clinical controversy, including the use of MRI, the safety of breast conservation, the role of neoadjuvant chemotherapy and the utility of genomic assays in patients with ILC. Citation Format: T. King. The Challenges of Lobular Carcinoma [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr ED02-02.

Immunohistochemical marker profiles for the differentiation of collagenous spherulosis from adenoid cystic carcinoma of the breast

Collagenous spherulosis (CS) is a rare breast lesion of unknown histogenesis. Adenoid cystic carcinoma (ACC) is a rare basal-like breast carcinoma with low histological grade. CS is a benign lesion but resembles ACC. Both lesions show a similar histomorphology and feature bilineage differentiation. This study compared immunohistochemical markers in CS and ACC.We compiled n = 13 CS cases and n = 18 mammary ACCs. Fourteen marker proteins (ER, PR, HER2, GATA3, CK7, E-cadherin, CD117, CK5/14, p40, p63, SMA, CD10, calponin, P-cadherin) were evaluated by immunohistochemistry (IHC). MYB rearrangement, a common alteration in ACC, was assessed by fluorescence in situ hybridization.Patient age ranged between 40-60 years for CS lesions and 30–90 years for ACCs. 7/13 (54%) CS cases harbored a lobular carcinoma in situ (LCIS) in the luminal component. One CS/LCIS lesion occurred in a carrier of a pathogenic germline variant in CDH1/E-cadherin. MYB rearrangement was detected in 0/11 (0%) CS and 6/16 (37%) ACC cases (P = 0.054). CS was associated with expression of ER in the luminal component (P < 0.001), E-cadherin loss in the luminal component (P = 0.045), and expression of CD10 and calponin in the basal component (P < 0.001). Furthermore, CS was associated with GATA3 expression in the luminal component (12/13 [92%] versus 5/18 [27%], P < 0.001).In summary, IHC for GATA3 and E-cadherin may contribute to the differential diagnosis between CS and ACC, although these markers are not exclusively expressed in either lesion. Histologic evaluation has to take into account that CS is frequently colonized by LCIS, requiring thorough correlation of histomorphology and immunohistochemical features.

Atypia Involving Fibroadenomas: Outcomes and Upgrade Rates.

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. 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. 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. 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.

Immediate and delayed risk of breast cancer associated with classic lobular carcinoma in situ and its variants.

To determine the risk of breast cancer due to lobular carcinoma in situ (LCIS). This retrospective IRB-approved study identified cases of LCIS after percutaneous breast biopsy from 7/2005 to 7/2022. Excluded were cases with less than 2years of imaging surveillance or a concurrent ipsilateral breast cancer diagnosis within 6months of the LCIS diagnosis. Final outcomes of cancer versus no cancer were determined by pathology at surgical excision or the absence of cancer on imaging surveillance. A total of 116 LCIS lesions were identified. The primary imaging findings targeted for percutaneous biopsy included calcifications (50.0%, 58/116), MR enhancing lesions (25.0%, 29/116), noncalcified mammographic architectural distortions (10.3%, 12/116), or masses (14.7%, 17/116). Surgical excision was performed in 49.1% (57/116) and imaging surveillance was performed in 50.9% (59/116) of LCIS cases. There were 22 cancers of which 11 cancers were discovered at immediate excision [19.3% (11/57) immediate upgrade] and 11 cancers developed later while on imaging surveillance [18.6% (11/59) delayed risk for cancer]. Among all 22 cancers, 63.6% (14/22) occurred at the site of LCIS (11 at immediate excision and 3 at surveillance) and 36.4% (8/22) occurred at a location away from the site of LCIS (6 in a different quadrant and 2 in the contralateral breast). LCIS has both an immediate risk (19.3%) and a delayed risk (18.6%) for cancer with 90.9% occurring in the ipsilateral breast (63.6% at and 27.3% away from the site of LCIS) and 9.1% occurring in the contralateral breast.

Cytoplasmic Expression of p16 Is Associated with Carcinoma Breast: It Is Not an Artifact.

p16 has different roles in the nuclear and cytoplasmic locations. The nuclear localization of the p16 protein explains its role in cell cycle regulation. Cytoplasmic expression was considered an artifact in the initial years, but there is evidence to prove that cytoplasmic localization is real and that p16 has different roles in the nuclear and cytoplasmic locations. We aimed to study the immunoexpression of p16 protein in the nuclear and cytoplasmic locations of the epithelial and stromal compartments of fibroadenoma, invasive breast carcinoma, and a select number of phyllodes tumors. The study included a total of 107 patients, comprising 51 cases of invasive breast carcinoma, 51 cases of fibroadenoma, 4 cases of benign phyllodes tumors, and 1 case of lobular carcinoma in situ (LCIS). The p16 immunohistochemistry was evaluated for nuclear and cytoplasmic localization in the epithelial and stromal compartments of the tumors. Of the 51 fibroadenoma cases, 23 showed strong nuclear p16 epithelial expression, but no case showed cytoplasmic expression. In 19/51 cases, stromal cells also showed strong p16 nuclear expression. Moderate stromal p16 expression was observed in 3 out of 4 cases of benign phyllodes. Out of the 51 cases of invasive carcinoma, 31 showed moderate to strong nuclear p16 immunopositivity, while 27 cases exhibited cytoplasmic p16 expression. We found a statistically significant correlation between moderate to strong nuclear p16 immunoexpression and the molecular subtype of breast carcinoma. The cytoplasmic localization of p16 immunohistochemistry is not seen in epithelial components of fibroadenoma, while it is seen frequently in breast carcinoma. Nuclear p16 expression has a statistically significant correlation with molecular subtypes of breast carcinoma.

Motley and Immured-Lobular Carcinoma In situ Pleomorphic

Pleomorphic lobular carcinoma in situ represents as an exceptionally discerned, morphological subtype of lobular carcinoma in situ (LCIS). Neoplasm is contemplated to express a genetic and biological advancement of classic lobular carcinoma in situ and emerges as a direct precursor to invasive carcinoma breast. Initially scripted by Frost et al in 1996, pleomorphic lobular carcinoma in situ is contemplated as a morphologic variant of classic lobular carcinoma in situ.

Surgical treatment of breast precancers - our experience.

Thanks to mammographic screening and the improvement of breast cancer diagnostics, the detection of precancers is also increasing. They are defined as morphological changes of the mammary gland which are more likely to cause cancer. The evaluated precancers are atypical ductal hyperplasia (ADH), lobular carcinoma in situ (LCIS) and radial scar. In the period 1. 1. 2018-31. 12. 2022, we performed 1,302 planned operations for breast disease at the Surgical Clinic of Teaching Hospital Plzeň, of which 30 (2%) were precancer operations. ADH was confirmed 11×, LCIS 8×, and a radical scar 11×. The average age of the patients in all three groups was 56 years (27-85). Precancer was diagnosed 8× only by sonography, 3× by mammography and 19× by a combination of both methods. Subsequently, a puncture biopsy was always completed. We performed 28 tumor excisions with intraoperative biopsy and 2 mastectomies. In the case of ADH from puncture biopsy, ADH was confirmed intraoperatively 8×, DCIS was diagnosed 2×, and mucinous carcinoma 1×. In LCIS, no tumor wasfound by intraoperative biopsy 4×, LCIS was confirmed 1×, lobular invasive carcinoma was diagnosed 1×, mastectomy was performed 2× without intraoperative biopsy. In the radial scar, ADH was diagnosed 3×, sclerosing adenosis 6×, DCIS 1×, invasive carcinoma 1×. After the final histological processing of the samples, there was an increase in diagnosed carcinomas. In ADH, DCIS was confirmed 3×, DIC 2×, and mucinous carcinoma 1×. In LCIS, LIC was diagnosed 3×. In the radial scar, DCIS was confirmed 1×, and invasive carcinoma remain 1×. Thus, carcinoma was diagnosed in 11 patients (37%) thanks to the surgical solution. No patient underwent axillary node surgery. All 11 patients subsequently underwent oncological treatment, always a combination of radiotherapy and hormone therapy. All patients are alive, 10 patients are in complete remission of the disease, one with DCIS experienced a local recurrence after 4 years. Surgical treatment of precancers of the breast makes sense, DCIS or even invasive cancer is often hidden in addition to precancer. Thanks to the surgical solution, the cancer was detected in time.

Microinvasive lobular carcinoma arising in abenign phyllodes tumour - ashort report and brief review of the literature.

Lobular carcinoma in situ (LCIS) with microinvasion is arare entity which is rarely reported in the literature. We describe acase of microinvasive LCIS following excision of afibroepithelial lesion. The lesion was graded as U3 and M3 on ultrasonography and mammography respectively, and on core needle biopsy was described as afibroepithelial lesion with 'unusual features'. Microscopic examination revealed afibroepithelial lesion focally colonised by florid E-cadherin negative LCIS with multiple foci of microinvasive classical lobular carcinoma, which lacked amyoepithelial layer on CK5 and S100 staining.

Huddled and Preternatural- Atypical Lobular Hyperplasia

Atypical lobular hyperplasia manifests as a clonal proliferation of dis-cohesive epithelial cells emerging from terminal duct lobular units. Neoplasm appears reminiscent of lobular carcinoma in situ (LCIS) although cellular quantification is reduced. Characteristically, the incidentally discovered lesion is associated with dysfunction or decimation of E-cadherin. Additionally designated as lobular intraepithelial neoplastic 1 (LIN1), tumefaction exemplifies a female preponderance. Typically, adult subjects are implicated. Tumefaction is commonly encountered within the fifth decade although no age of disease emergence is exempt. Atypical lobular hyperplasia is detected within&lt;1% of core needle biopsies adopted for evaluating BI-RADS 4 lesions [1,2]. Atypical lobular hyperplasia may incriminate bilateral breasts wherein specific lesion localization is absent. Tumefaction exhibits loss of chromosome 16qand deletion of CDH1 genes with loss of function of E-cadherin, a Tran’s membrane cell adhesion molecule. Alternatively, altered function of E-cadherin may occur. Exceptionally, various adhesion proteins are implicated wherein E-cadherin molecule appears stable [1,2]. Characteristically, atypical lobular hyperplasia is a diploid neoplasm. Tumefaction exhibits loss of heterozygosis (LOH) at chromosome 16q. A subset of neoplasms demonstrates methylation of CDH1 gene. Several tumefaction express loss of chromosome 22q and 16p, gain of chromosome 2p11.2, 5q32- 33.1 (CSF1R), 6q, 11q13 or 14q32.33.

Update on Lobular Neoplasia.

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

DCIS and LCIS: Are the Risk Factors for Developing In Situ Breast Cancer Different?

Ductal carcinoma in situ (DCIS) is widely accepted as a precursor of invasive ductal carcinoma (IDC). Lobular carcinoma in situ (LCIS) is considered a risk factor for invasive lobular carcinoma (ILC), and it is unclear whether LCIS is also a precursor. Therefore, it would be expected that similar risk factors predispose to both DCIS and IDC, but not necessarily LCIS and ILC. This study examined associations with risk factors using data from 3075 DCIS cases, 338 LCIS cases, and 1584 controls aged 35-60, recruited from the UK-based GLACIER and ICICLE case-control studies between 2007 and 2012. Analysis showed that breastfeeding in parous women was protective against DCIS and LCIS, which is consistent with research on invasive breast cancer (IBC). Additionally, long-term use of HRT in post-menopausal women increased the risk of DCIS and LCIS, with a stronger association in LCIS, similar to the association with ILC. Contrary to findings with IBC, parity and the number of births were not protective against DCIS or LCIS, while oral contraceptives showed an unexpected protective effect. These findings suggest both similarities and differences in risk factors for DCIS and LCIS compared to IBC and that there may be justification for increased breast surveillance in post-menopausal women taking long-term HRT.

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

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

Optimized Modeling of Metastatic Triple-Negative Invasive Lobular Breast Carcinoma.

Invasive lobular carcinoma (ILC) is a common breast cancer subtype that is often diagnosed at advanced stages and causes significant morbidity. Late-onset secondary tumor recurrence affects up to 30% of ILC patients, posing a therapeutic challenge if resistance to systemic therapy develops. Nonetheless, there is a lack of preclinical models for ILC, and the current models do not accurately reproduce the complete range of the disease. We created clinically relevant metastatic xenografts to address this gap by grafting the triple-negative IPH-926 cell line into mouse milk ducts. The resulting intraductal xenografts accurately recapitulate lobular carcinoma in situ (LCIS), invasive lobular carcinoma, and metastatic ILC in relevant organs. Using a panel of 15 clinical markers, we characterized the intratumoral heterogeneity of primary and metastatic lesions. Interestingly, intraductal IPH-926 xenografts express low but actionable HER2 and are not dependent on supplementation with the ovarian hormone estradiol for their growth. This model provides a valuable tool to test the efficiency of potential new ILC therapeutics, and it may help detect vulnerabilities within ILC that can be exploited for therapeutic targeting.