Pleomorphic lobular carcinoma of the breast: role of comprehensive molecular pathology in characterization of an entity

Comparison of Clinicopathologic Features and Survival Outcomes of Pleomorphic Lobular, Classical Lobular, and Invasive Ductal Carcinoma

PURPOSE

The objective of this research is to assess the clinical importance of pleomorphic lobular carcinoma (PLC) by contrasting its survival outcomes and clinicopathological characteristics with those of classical invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC).

METHODS

Data from the SEER (Surveillance, Epidemiology, and End Results) database, which covers patients with breast cancer diagnosed between 2010 and 2021, are used in this retrospective analysis. Clinical, pathological, and demographic factors were noted. Kaplan-Meier and Cox regression models were used to conduct survival analyses.

RESULTS

A total of 639,943 patients were included in the study. 182 (0.03%) patients were diagnosed with PLC, 74,565 (11.6%) were with ILC, and 565,196 (88.3%) were with IDC. Compared with ILC and IDC, PLC was associated with higher tumor grade, higher T, N stage, and stage 3-4 AJCC stage, higher hormone negativity, and triple negativity rates. Breast-conserving surgery (BCS) rates were lower in the PLC group, whereas mastectomy, no surgery, and chemotherapy rates were higher. Five-year and 10-year overall survival (OS) and disease-specific survival (DSS) rates were significantly lower in the PLC group than in both ILC and IDC (p < 0.05). However, when survival outcomes were evaluated according to stage, no statistically significant differences in overall survival (OS) or disease-specific survival (DSS) were found between PLC and ILC or between PLC and IDC across all disease stages (p > 0.05).

CONCLUSION

PLC, a very rare type of breast cancer, has worse clinicopathological features and worse survival outcomes than both ILC and IDC. These findings highlight the need for more specialized personalized targeted therapeutic strategies for PLC.

Nuclear morphological characterisation of lobular carcinoma variants: a morphometric study

BACKGROUND AND AIMS

Lobular carcinoma (LC) of the breast exhibits diverse morphology and clinical behaviour. The pleomorphic variant (pLC) displays distinct cytonuclear features and aggressiveness compared to the classic variant (cLC). However, diagnosing pLC remains subjective. This study aims to refine LC's cytonuclear features, focusing on pLC.

METHODS

Whole slide images of 59 LCs, including both in situ (LCIS) and invasive (ILC) lesions, were analysed. Nuclear measurements, including nuclear size and variability, were scored using QuPath image analysis software. For comparison, selected features were scored in normal cells (n = 10) and pleomorphism score-matched invasive breast carcinoma (IBC) of NST type (n = 33). Additional visual assessment of the pleomorphic ILC (pILC) cohort (n = 90) was conducted for cytomorphological features characterisation.

RESULTS

pILC demonstrated larger nuclear area and higher nuclear variability with abundance of cytoplasm than cILC. Compared to lymphocytes, pILC demonstrated a median area ranging from 2.7 to 4.7 times larger. Cut-off values for differentiating pILC from other ILC subtypes included median nuclear area > 48.2 μm2 and interquartile range (IQR) > 19.4, nuclear perimeter median > 25.2 μm and IQR > 5.3 and maximum diameter > 9.1 μm and IQR > 2.2. Multivariable logistic regression confirmed these parameters as independent predictors of pILC, with the maximum diameter being the most significant (P < 0.001). Visual assessment recognised two pILC subtypes: apocrine and non-apocrine. Apocrine variant showed nuclear roundness, pale vesicular chromatin patterns and prominent nucleoli, while non-apocrine variant exhibited greater nuclear size and shape variation.

CONCLUSIONS

Objective nuclear measurements, combined with cytoplasmic and architectural features, provide a robust framework for diagnosing LC subtypes, improving diagnostic accuracy and reproducibility.

Surgery for Classic, Pleomorphic and Non-classic Lobular Carcinoma In Situ: Surgery Rate, Risk of Upstaging and Short-Term Follow-Up

BACKGROUND

The Dutch breast cancer guideline recommends surveillance for classic lobular carcinoma in situ (LCIS), unless there is a discrepancy with mammographic findings, and surgery for pleomorphic and non-classic LCIS.

OBJECTIVE

The aim of this study was to assess adherence to the guideline in daily practice, as well as the surgery rate, risk of upstaging, and events during follow-up.

METHODS

Selection of patients from a nationwide cohort diagnosed between 2011 and 2020. Patients with a history of in situ or invasive breast cancer or concomitant atypical ductal hyperplasia were excluded. Analyses comprised univariable analysis.

RESULTS

Of 1178 diagnoses, 1018 (86%) were classic LCIS, 129 (11%) were pleomorphic LCIS, and 31 (3%) were non-classic (florid or unspecified non-classic) LCIS. Surgery was performed in 323 patients. The surgery rate for classic LCIS was 19%, 83% for pleomorphic LCIS, and 84% for non-classic LCIS. The upstage rate for both classic and pleomorphic LCIS was 32%, and 31% for non-classic LCIS. LCIS was upstaged in 103 patients (32%); 24 (7%) to DCIS and 79 (25%) to invasive breast cancer. Follow-up of the 859 non-operated patients showed fewer than 4% with ipsilateral DCIS or invasive breast cancer.

CONCLUSION

The surgery rates for classic, pleomorphic, and non-classic LCIS indicate that the guideline is well adhered to in daily practice. Given the high upstage rates and low number of subsequent DCIS and invasive breast cancer events in patients with classic LCIS, these patients appear to be well-selected for surgery versus surveillance. The results support the recommendation to operate on patients with pleomorphic/non-classic LCIS.

"Lobular lesions of the breast: From the classic to the variants"

The aim of this review is to provide the surgical pathologist an overview of lobular lesions, from in situ to invasive carcinoma and the variants, by discussing the epidemiology, clinical characteristics, morphology, immunohistochemistry, known molecular data as well as the treatment recommendations. The recognition of histologic variants of both in situ and invasive lobular carcinoma has expanded the differential diagnosis. Awareness of these different entities is important as treatment recommendations continue to evolve.

Comparison of Clinicopathological Features of Pleomorphic and Invasive Lobular Breast Carcinomas

PURPOSE

Accounting for about 15% of invasive lobular carcinomas and 1% of breast carcinomas, pleomorphic lobular carcinoma is known to be a rare histological subtype of invasive lobular carcinoma. Yet, it is more aggressive and produces a worse prognosis than other breast cancers. Ultimately, the present study compares the clinicopathological features of pleomorphic and invasive lobular breast carcinomas.

METHODS

In the study, we retrospectively evaluated the data of 262 patients with histological subtypes of classical and pleomorphic lobular cancers having been recruited for surgical operations. After resorting to Kolmogorov-Smirnov and Shapiro-Wilk tests to check the normality of distribution, the categorical and continuous variables were compared between the groups using the chi-square test and independent samples t test, respectively. In all analyses, we considered a P-value of <.05 to be statistically significant.

RESULTS

Our findings revealed that the groups with lobular and pleomorphic groups significantly differed by Ki-67 value, estrogen receptor negativity, grade, multicentricity, multifocality, surgical margin positivity, completion mastectomy, and metachronous contralateral tumor (P < .05).

CONCLUSION

We discovered that pleomorphic type was associated with higher grades, estrogen receptor negativity, and Ki-67 expression. The incidence of metachronous breast cancer was high in the pleomorphic group, which may be a noteworthy finding to be considered in follow-ups. In addition, the high rates of multicentricity and multifocality of tumors in the pleomorphic group may be associated with increased surgical margin positivity and a higher likelihood of mastectomy. In a nutshell, our findings may guide patients and surgeons regarding the type of intervention and reconstruction options to be adopted in prospective surgeries.

The morphologic spectrum of lobular carcinoma in situ (LCIS) observations on clinical significance, management implications and diagnostic pitfalls of classic, florid and pleomorphic LCIS

Lobular carcinoma in situ (LCIS) is a non-invasive proliferation of atypical dyscohesive epithelial cells characterized by loss or functional alteration of E-cadherin-mediated cell adhesion. The morphologic spectrum of LCIS encompasses classic (C-LCIS), florid (F-LCIS) and pleomorphic LCIS (P-LCIS), as recently defined by the World Health Organization (WHO) Expert Consensus Group. Atypical lobular hyperplasia (ALH) is also part of this spectrum.This article highlights the morphologic and immunohistochemical features of the three forms of LCIS and summarizes their management implications and prognosis, with emphasis on F-LCIS and P-LCIS.

Biomarker profile of invasive lobular carcinoma: pleomorphic versus classic subtypes, clinicopathological characteristics and prognosis analyses

PURPOSE

To compare the clinicopathologic features and prognosis of pleomorphic invasive lobular carcinoma (P-ILC) and classic ILC (C-ILC) according to the biomarker profile.

METHODS

A total of 667 C-ILCs and 133 P-ILCs between 2011 and 2021 were included. Clinicopathologic features and stromal tumor-infiltrating lymphocytes (sTILs) status were evaluated. P-ILCs were divided into subtypes based on ER/PR and HER2 expression. The overall survival and disease-free survival (DFS) of patients were compared among matched P-ILCs, C-ILCs, and invasive ductal carcinomas (IDCs) with biomarker subtypes.

RESULTS

Compared to C-ILCs, P-ILCs had greater tumor sizes and stages, fewer ER-positive, more HER2-positive, triple negative (TN), and Ki-67 > 20% tumors (P < 0.05). P-ILCs were subdivided into ER+ (63.1%), HER2+ (21.1%) and TN (15.8%). ER+ P-ILCs were mainly showed trabecular and solid growth patterns. Apocrine and solid features were more strongly associated with HER2+ P-ILCs and TN-P-ILCs, respectively. The prognosis of each biomarker group (ER+, HER2+ and TN) differed by subtype. The P-ILC biomarker subtypes had worse prognosis than the same subtypes in the IDC group, while there was no difference between the P-ILC and the C-ILC counterparts. Solid variants of P-ILC had the worst prognosis. Bone was the most common metastatic site in ER+ P-ILCs and TN-P-ILCs. HER2+ P-ILCs tended to metastasize to the brain and liver. DFS of HER2+ P-ILCs and TN-P-ILCs were worse than that of ER+ P-ILCs. Lacking lobular carcinoma in situ and sTILs ≤ 10% were associated with worse survival of ER+ P-ILCs and TN-P-ILCs, respectively. For HER2+ P-ILCs, Ki-67 > 20% and sTILs ≤ 10% were significant factors for lower DFS.

CONCLUSION

P-ILCs is an aggressive subtype of ILCs. Analyzing the prognostic factors of P-ILCs with heterogeneous morphological and biomarker characteristics is helpful for creating an individualized treatment.

Salivary Duct Carcinoma With Rhabdoid Features-No or Aberrant Expression of E-cadherin and Genetic Changes in CDH1: Immunohistochemical and Genetic Analyses of 17 Cases

Salivary duct carcinoma is a relatively uncommon malignancy of the salivary glands; however, it frequently occurs as a carcinomatous component of carcinoma ex pleomorphic adenoma. We previously reported salivary duct carcinoma with rhabdoid features (SDCRF) as an extremely rare subtype of salivary duct carcinoma, and that it occurred as a salivary counterpart of pleomorphic lobular carcinoma of the breast (PLCB). We collected new cases of SDCRF for this study, in which we examined a total of 17 cases immunohistochemically and genetically. As it is known that PLCB exhibits loss of or aberrant E-cadherin expression and carries nonsense/missense mutations in or deletion of the CDH1 gene, we examined the CDH1 gene status of our SDCRF cases. All of the examined SDCRF cases involved the diffuse proliferation of large ovoid cells with eosinophilic cytoplasm and eccentric nuclei, which displayed reduced cell-cell adhesion. Most cases were positive for pan-cytokeratin, androgen receptor, gross cystic disease fluid protein-15, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1, and WI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 4, whereas they were negative for vimentin. No and decreased/cytoplasmic E-cadherin expression was observed in 11 and 4 of 17 cases, respectively, whereas no and decreased/cytoplasmic β-catenin expression were observed in 10 and 5 of 17 cases, respectively. Among the 11 cases that could be genetically analyzed, a nonsense mutation (1 case), missense mutations (6 cases), and insertions (1 case) were detected in the CDH1 gene. In conclusion, we propose that SDCRF is the salivary counterpart of PLCB due to its morphology and immunophenotype, and the genetic status of CDH1.

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

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

Invasive pleomorphic lobular carcinoma of the breast with multiple metastases: A case report

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Invasive Pleomorphic Lobular Carcinoma(IPLC) accounts for less than 1% of breast cancer.

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This paper reports a case of IPLC with multiple metastases and gives review literature.

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The patient’s general condition improved after our specific treatment options, which has a certain reference for the treatment of this kind of patients in the future.

Introduction and importance

IPLC (Invasive Pleomorphic Lobular Carcinoma) accounts for less than 1% of breast cancer. To the best of our knowledge, this is one of the few reported cases in the IPLC with multiple metastases. The patient's general condition got improved after our treatment, which has a certain reference for the treatment of this kind of patient in the future.

Case presentation

A 42-year-old female with IPLC and multiple metastases. The IPLC malignant cells were positive for p120 (cytoplasmic) and human epidermal growth factor receptor 2, negative for estrogen receptor, progesterone receptor, and E-cadherin. There were nodular enhancement foci in the liver, which are considered the metastatic lesions of the breast, and the liver function was abnormal. Multiple metastatic lesions of the vertebral body, appendage of the whole spine, and sternum. And C7, T1, and T9 vertebrae showed compression fractures.

Clinical discussion

IPLC has systemic metastasis which molecular typing by immunohistochemistry is HER-2 overexpression can choose chemotherapy combined with targeted therapy to prolong the survival time and improve the quality of life of patients. The patient was followed up.

Conclusions

This paper reports a case of IPLC with multiple metastases and gives review literature. Our treatment of the patient can be a reference for other clinicians.

Targetable alterations in invasive pleomorphic lobular carcinoma of the breast

Background

Invasive pleomorphic lobular carcinoma (PLC) of the breast is a subtype of invasive lobular cancer which compromises approximately 1% of all epithelial breast malignancies and is characterized by higher nuclear pleomorphism and poorer prognosis than classic invasive lobular cancer (ILC). Since PLC is more aggressive than classical ILC, we examined the underlying molecular alterations in this subtype of breast cancer to understand the possible benefit from targeted therapies.

Methods

In this study, we investigate the clinical characteristics and molecular alterations in 16 PLC from our institution. Additionally, we examined the clinical and genomic features in 31 PLC from the Cancer Genome Atlas (TCGA).

Results

Overall, our analysis of PLC found that 28% had activating ERBB2 mutations, 21% had ERBB2 amplification, and 49% activating PIK3CA mutations. Among cases from our institution, we found 19% with activating ERBB2 mutations, 25% had ERBB2 amplification, and 38% with activating PIK3CA mutations. In data from TCGA, 32% had activating ERBB2 mutations, 19% had ERBB2 amplification, and 55% had activating PIK3CA mutations. While classic ILC in TCGA had similar percentages of PIK3CA alterations compared to PLC, activating ERBB2 alterations were exceedingly rare, with no activating ERBB2 mutations and only one case with ERBB2 amplification. Interestingly, in further examining TCGA data which included FGFR1 and PTEN, 94% of PLC had alterations in ERBB2, FGFR1, or the PI3K pathway.

Conclusions

Our results show a high frequency of ERBB2 and PIK3CA alterations in PLC and suggest all PLC should be tested for potential therapeutic targeting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-020-01385-5.

Lobular carcinoma in situ: diagnostic criteria and molecular correlates

Lobular neoplasia (LN) is an atypical proliferation of small, dyscohesive epithelial cells within the terminal duct lobular unit (TDLU), with or without pagetoid extension and encompasses both lobular carcinoma in situ (LCIS) and atypical lobular hyperplasia (ALH). LN is a non-obligate precursor of invasive breast carcinoma and the diagnosis of LN confers an increased risk of invasive carcinoma development, compared to the general population. Diagnostic challenges arise in the accurate classification of LCIS into classic, pleomorphic and florid subtypes, in distinguishing between LCIS and ductal carcinoma in situ (DCIS) and in the appropriate use and interpretation of E-cadherin immunohistochemistry. Due to the paucity of robust data on the natural history of LCIS, and hence its clinical significance, the management is often pragmatic rather than entirely evidence-based and requires a multidisciplinary approach. In this review, we discuss the clinicopathologic and molecular features of LCIS and address the key challenges that arise in the diagnosis and management of LCIS.

Clinicopathological and Molecular Characteristics of Pleomorphic Invasive Lobular Carcinoma

Pleomorphic invasive lobular carcinoma (PILC) is a distinct morphological and biologically aggressive variant of invasive lobular carcinoma (ILC). We hypothesized that was due to de novo activation of PI3K/Akt/mTOR pathway in PILC resulting in higher proliferation rate and markers of cell cycle activation. We identified PILC and ILC tumors and tested for PI3K/Akt/mTOR pathway activation by immunohistochemistry (PTEN and pS6K1) and gene expression analysis (by Nanostring nCounter system). Proliferation index (Ki67) was elevated in 85% of PILCs compared to 20% of ILCs (p < 0.007). PTEN expression was high in all while pS6K1 was high in 8/9 PILCs compared to 3/9 ILCs (p < 0.007). Gene expression analysis shows that PILCs have overexpression of genes involved in cell cycle proliferation, cellular proliferation, DNA damage, and repair genes but no difference in PI3K/Akt/mTOR pathway genes. PILCs are a biologically distinct group of ILC, and clinicopathological characteristics suggest they would have a more clinically aggressive behavior. In addition, our results indicate that PI3k/Akt/mTOR pathway and cell cycle proliferation are activated in majority of these tumors. Further studies are needed to investigate these mechanisms as there are approved therapies available that may benefit PILCs.

Triple-negative pleomorphic lobular carcinoma and expression of androgen receptor: Personal case series and review of the literature

Pleomorphic lobular carcinoma (PLC) is a histological variant of invasive lobular carcinoma (ILC) and is associated with worse prognosis than classical ILC. It exhibits a greater degree of cellular atypia and pleomorphism and is occasionally accompanied with apocrine morphology. We investigated the immunohistochemical characteristics of samples from 31 Japanese patients with PLC to elucidate the clinicopathological characteristics of PLC including androgen receptor (AR) immunoreactivity. The surrogate molecular subtypes were luminal A-like, luminal B-like, luminal B-like/HER2, HER2-type, and triple-negative in 5, 4, 3, 5, and 14 cases, respectively. AR was positive in 92.8% (13/14) of the triple-negative PLC cases and 100% (10/10) of the non-triple-negative PLC cases. Disease-specific survival was worse in patients with histological grade 3 PLCs than in those with histological grade 2 PLCs (p = 0.007). However, there was no significant difference in the progression-free survival between the two groups (p = 0.152). No other clinicopathological characteristics were associated with prognosis. These results reveal that PLC exhibits various surrogate molecular subtypes and that the triple-negative subtype frequently expresses AR. The observed molecular apocrine differentiation implicates that triple-negative PLC can be categorized into the luminal AR subtype. Furthermore, AR-targeted therapy might be useful for patients with triple-negative PLC.

Non-invasive lobular neoplasia of the breast: Morphologic features, clinical presentation, and management dilemmas

The designation of noninvasive lobular neoplasia applies to atypical epithelial proliferations composed of noncohesive cells secondary to loss or functional alteration of E-cadherin-mediated cell adhesion. The morphologic spectrum of noninvasive lobular neoplasia encompasses atypical lobular hyperplasia (ALH) and classic lobular carcinoma in situ (classic LCIS) and two LCIS variants, namely florid LCIS (F-LCIS) and pleomorphic LCIS (P-LCIS), as defined in the World Health Organization (WHO) Classification of Tumors of the Breast 5th ed. Herein, we review the morphologic, immunohistochemical, and molecular features of noninvasive lobular neoplasia, with special emphasis on F-LCIS and P-LCIS. We also review imaging features, management at core needle biopsy, upgrade rates at surgical excision, and clinical management dilemmas.

Genetic analysis of pleomorphic and florid lobular carcinoma in situ variants: frequent ERBB2/ERBB3 alterations and clonal relationship to classic lobular carcinoma in situ and invasive lobular carcinoma

Pleomorphic (PLCIS) and florid (FLCIS) lobular carcinoma in situ are rare histologic variants of LCIS that are considered more aggressive than classic LCIS (CLCIS), but optimal treatment is controversial. The genetic drivers of these lesions and their clonal relationships to paired CLCIS and ILC have not been characterized. We used capture-based next-generation sequencing to profile 16 LCIS variants (ten PLCIS, six FLCIS), including paired synchronous ILC and CLCIS in 11 and nine cases, respectively. Recurrent pathogenic alterations included CDH1 (9/10 PLCIS, 6/6 FLCIS), PIK3CA (7/10 PLCIS, 2/6 FLCIS), ERBB2 (6/10 PLCIS, 2/6 FLCIS; six mutations, two amplifications), ERBB3 (1/10 PLCIS, 2/6 FLCIS), FOXA1 (4/10 PLCIS, 1/6 FLCIS), TP53 (3/10 PLCIS), and CCND1 (2/10 PLCIS, 1/6 FLCIS). Mutational profiles and mean copy number alterations (CNA) were similar between LCIS variants with and without ILC. Compared with ILC in The Cancer Genome Atlas (TCGA), PLCIS, FLCIS, and associated ILC were enriched for ERBB2 mutations, and PLCIS was enriched for TP53 and FOXA1 mutations. Shared pathogenic mutations and CNA were identified between the LCIS variant and ILC in all cases, and between CLCIS and the LCIS variant/ILC in 89%. CLCIS to PLCIS progression was associated with increased mean nonsynonymous mutations and additional pathogenic alterations and/or CNA in 80%. Mean nonsynonymous mutations and CNA were similar between PLCIS and ILC, although additional pathogenic mutations were associated with invasion in a subset (43%). FLCIS harbored additional clonal pathogenic mutations in only 1/3 cases, and these were not shared with ILC, which was genetically divergent. In another case, ILC was genetically more similar to CLCIS than FLCIS. The results highlight clonal relationships between PLCIS/FLCIS and CLCIS, and implicate PLCIS as a genetically advanced ILC precursor. Frequent ERBB2/ERBB3 alterations in PLCIS and FLCIS are consistent with more aggressive behavior and may have prognostic and therapeutic implications.

Mitotic score and pleomorphic histology in invasive lobular carcinoma of the breast: impact on disease-free survival

PURPOSE

Pleomorphic invasive lobular carcinoma (ILC) has long been thought to have worse outcomes than classic ILC and is therefore often treated with chemotherapy. However, recent data question the utility of the pleomorphic designation, as the poor outcomes seen may be related to other associated high-risk features. Importantly, mitotic count may better define a subset of ILC with high risk of recurrence. We sought to determine the impact of pleomorphic histology versus mitotic count on disease-free survival (DFS) in pure ILC. Additionally, we evaluated whether pleomorphic histology was associated with receipt of chemotherapy when adjusting for other factors.

METHODS

We analyzed a cohort of 475 patients with stage I-III pure ILC. We used Kaplan-Meier estimates, and Cox proportional hazards and logistic regression for multivariate analyses. Pleomorphic histology was confirmed by central pathology review.

RESULTS

In a multivariate model, pleomorphic histology was not associated with reduced DFS. Only mitotic score, receptor subtype, and pathologic stage were independently and significantly associated with DFS. Patients with pleomorphic ILC were significantly more likely to receive chemotherapy than patients with classic ILC (adjusted odds ratio 2.96, p = 0.026).

CONCLUSIONS

The pleomorphic designation in ILC does not have clinical utility and should not be used to determine therapy. Rather, mitotic count identified clear prognostic groups in this cohort of pure ILC.

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.

High Frequency of ERBB2 Activating Mutations in Invasive Lobular Breast Carcinoma with Pleomorphic Features

Background: Characterisation of molecular alterations of pleomorphic lobular carcinoma (PLC), an aggressive subtype of invasive lobular carcinoma (ILC), have not been yet completely accomplished. Methods: To investigate the molecular alterations of invasive lobular carcinoma with pleomorphic features, a total of 39 tumour samples (in situ and invasive lesions and lymph node metastases) from 27 patients with nuclear grade 3 invasive lobular carcinomas were subjected to morphological, immunohistochemical and massive parallel sequencing analyses. Results: Our observations indicated that invasive lobular carcinomas with pleomorphic features were morphologically and molecularly heterogeneous. All cases showed absence or aberrant expression of E-cadherin and abnormal expression of β-catenin and p120. CDH1 (89%), PIK3CA (33%) and ERRB2 (26%) were the most common mutated genes. ERBB2 mutations preferentially affected the tyrosine-kinase activity domain, being the most frequent the targetable mutation p.L755S (57%). We also observed higher frequency of mutations in ARID1B, KMT2C, MAP3K1, TP53 and ARID1A in PLC than previously reported in classic ILC. Alterations related to progression from in situ to invasive carcinoma and/or to lymph node metastases included TP53 mutation, amplification of PIK3CA and CCND1 and loss of ARID1A expression. Conclusions: The high frequency of ERBB2 mutations observed suggests that ERBB2 mutation testing should be considered in all invasive lobular carcinomas with nuclear grade 3.

Evaluating agreement, histological features, and relevance of separating pleomorphic and florid lobular carcinoma in situ subtypes

Morphological variants of lobular carcinoma in situ (LCIS) include classical (CLCIS), pleomorphic (PLCIS) and florid type (FLCIS). Treatment guidelines suggest managing PLCIS and FLCIS like ductal carcinoma in situ (DCIS); therefore accurate identification of LCIS subtypes is critical. However, the significance of separating PLCIS from FLCIS is not clear. Also, interobserver agreement in identifying LCIS subtypes, using contemporary criteria, is not known. We aimed to evaluate interobserver agreement amongst breast pathologists in diagnosing LCIS subtypes and use the agreement data to justify LCIS classification for management purposes. Six breast pathologists independently reviewed 50 hematoxylin and eosin-stained slides comprised of a mix of LCIS subtypes. After reviewing published criteria, participants diagnosed PLCIS, CLCIS and apocrine change in a marked region of interest and FLCIS based on entire section. PLCIS was identified in 8 to 37 slides with overall moderate agreement (Fleiss' κ = 0.565) and pairwise κ (Cohen's) ranging from -.008 to 0.492. FLCIS was diagnosed in 15-26 slides with overall substantial agreement (Fleiss' κ = 0.687) and pairwise κ ranging from -.068 to 0.706. Both FLCIS and PLCIS coexisted in 45% of slides with consensus on non-classical LCIS. Comedo-type necrosis (odds ratio = 5.5) and apoptosis (odds ratio = 1.8) predicted FLCIS. We found moderate and substantial agreement in diagnosing PLCIS and FLCIS respectively. Objective histological features linked with aggressive behavior were more frequent with FLCIS. PLCIS and FLCIS patterns frequently coexist, contain similar molecular aberrations, and are managed similarly (like DCIS); therefore, combining FLCIS and PLCIS into one category (non-classical LCIS) should be considered.

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.

Lobular Carcinoma In Situ

Lobular carcinoma in situ (LCIS) is a risk factor and a nonobligate precursor of breast carcinoma. The relative risk of invasive carcinoma after classic LCIS diagnosis is approximately 9 to 10 times that of the general population. Classic LCIS diagnosed on core biopsy with concordant imaging and pathologic findings does not mandate surgical excision, and margin status is not reported. The identification of variant LCIS in a needle core biopsy specimen mandates surgical excision, regardless of radiologic-pathologic concordance. The presence of variant LCIS close to the surgical margin of a resection specimen is reported, and reexcision should be considered.

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.

Expression of Lipid Metabolism-Related Proteins Differs between Invasive Lobular Carcinoma and Invasive Ductal Carcinoma

We comparatively investigated the expression and clinical implications of lipid metabolism-related proteins in invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) of the breast. A total of 584 breast cancers (108 ILC and 476 IDC) were subjected to tissue microarray and immunohistochemical analysis for lipid metabolism-related proteins including hormone-sensitive lipase (HSL), perilipin A, fatty acid binding protein (FABP)4, carnitine palmitoyltransferase (CPT)-1, acyl-CoA oxidase 1, and fatty acid synthetase (FASN). HSL, perilipin A, and FABP4 expression (all p < 0.001) differed significantly: HSL and FABP4 were more frequently present in ILC, whereas perilipin A was more frequently detected in IDC. Among all invasive cancers, HSL and FABP4 were highly expressed in luminal A-type ILC (p < 0.001) and perilipin A in luminal A-type IDC (p = 0.007). Among luminal B-type cancers, HSL and FABP4 were more highly expressed in ILC (p < 0.001). Univariate analysis found associations of shorter disease-free survival with CPT-1 positivity (p = 0.004) and acyl-CoA oxidase 1 positivity (p = 0.032) and of shorter overall survival with acyl-CoA oxidase 1 positivity (p = 0.027). In conclusion, ILC and IDC exhibited different immunohistochemical lipid metabolism-related protein expression profiles. Notably, ILC exhibited high HSL and FABP4 and low perilipin A expression.

Pleomorphic lobular carcinoma of the breast: a comparison of cytopathological features with other lobular carcinoma variants

OBJECTIVE

Pleomorphic lobular carcinoma (PLC) is a subtype of breast cancer with unique morphological features, but it remains controversial whether PLC should be considered an independent disease entity. The aim of this study was to illustrate cytopathological characteristics of PLC in comparison with other lobular carcinoma variants.

METHODS

We investigated clinicopathological features of PLC (n = 11) compared with those of other variants of invasive lobular carcinoma (ILC, non-PLC) (n = 32). Histological variants of the non-PLC group consisted of classic (n = 25), solid (n = 2), alveolar (n = 1) and a tubulolobular type (n = 4). A review of cytological reports and fine needle aspiration (FNA) smear samples was performed for the PLC (n = 9) and non-PLC (n = 27) groups.

RESULTS

Patients with PLC were older, and had a higher nuclear grade and a higher incidence of axillary lymph node metastasis and triple negative phenotype than non-PLC patients (P = 0.007, P < 0.001, P = 0.02 and P < 0.001, respectively). Cytological findings in PLC included medium- to large-sized nuclei, prominent nucleoli, a moderate-to-severe degree of pleomorphism, apocrine change and background necrosis, none of which were evident in the smears of the non-PLC group (P < 0.001, P = 0.002, P < 0.001, P < 0.001, and P = 0.03, respectively). Despite these differences, patients with PLC and non-PLC showed similar clinical outcomes in our follow-up period.

CONCLUSIONS

Based on our results, a cytological diagnosis of PLC should be proposed if there are moderate- to large-sized nuclei, prominent nucleoli, a moderate-to severe degree of nuclear pleomorphism, apocrine change and necrosis in the background in FNA biopsy samples.

Atypical epithelial hyperplasia of the breast: state of the art

INTRODUCTION

Atypical epithelial hyperplasia (AEH) of the breast is considered benign histological lesions with breast cancer risk. This review focuses on clinical signification and management of AEH that remains controversial.

AREAS COVERED

A review of published studies was performed using medline database. In this review, we fully describe the current evidence available. In particular, we describe 1) data from immunohistochemistry and molecular studies that suggest AEH is a precursor of breast cancer; 2) epidemiological studies demonstrate low rate of breast cancer in women with AEH; 3) surgical excision is necessary after diagnosis of AEH, such as lobular carcinoma in situ or atypical ductal hyperplasia, on core needle biopsy; 4) although current recommendations are evolving to fewer (if not no) excisions for flat epithelial with atypia and classic lobular neoplasia found on percutaneous biopsy (without radiologic indications for excision). Expert commentary: HEA management steel need prospective evidences, but recent retrospective data give some clue for less invasive management for some of HEA.

Methylation biomarkers for pleomorphic lobular breast cancer - a short report

Background

Pleomorphic invasive lobular cancer (pleomorphic ILC) is a rare variant of ILC that is characterized by a classic ILC-like growth pattern combined with an infiltrative ductal cancer (IDC)-like high nuclear atypicality. There is an ongoing discussion whether pleomorphic ILC is a dedifferentiated form of ILC or in origin an IDC with a secondary loss of cohesion. Since gene promoter hypermethylation is an early event in breast carcinogenesis and thus may provide information on tumor progression, we set out to compare the methylation patterns of pleomorphic ILC, classic ILC and IDC. In addition, we aimed at analyzing the methylation status of pleomorphic ILC.

Methods

We performed promoter methylation profiling of 24 established and putative tumor suppressor genes by methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) analysis in 20 classical ILC, 16 pleomorphic ILC and 20 IDC cases.

Results

We found that pleomorphic ILC showed relatively low TP73 and MLH1 methylation levels and relatively high RASSF1A methylation levels compared to classic ILC. Compared to IDC, pleomorphic ILC showed relatively low MLH1 and BRCA1 methylation levels. Hierarchical cluster analysis revealed a similar methylation pattern for pleomorphic ILC and IDC, while the methylation pattern of classic ILC was different.

Conclusion

This is the first report to identify TP73, RASSF1A, MLH1 and BRCA1 as possible biomarkers to distinguish pleomorphic ILC from classic ILC and IDC.

Invasive lobular carcinoma of the breast: morphology, biomarkers and 'omics

Invasive lobular carcinoma of the breast is the most common 'special' morphological subtype of breast cancer, comprising up to 15% of all cases. Tumours are generally of a good prognostic phenotype, being low histological grade and low mitotic index, hormone receptor positive and HER2, p53 and basal marker negative, and with a generally good response to endocrine therapy. Despite this, clinicians face countless challenges in the diagnosis and long-term management of patients, as they encounter a tumour that can be difficult to detect through screening, elicits a very invasive nature, a propensity for widespread metastatic colonisation and, consequently, in some studies a worse long-term poor outcome compared with invasive carcinoma of no special type. Here we review the morphological and molecular features that underpin the disparate biological and clinical characteristics of this fascinating tumour type.

Clinical outcome in pleomorphic lobular carcinoma: a case-control study with comparison to classic invasive lobular carcinoma

Pleomorphic lobular carcinoma (PLC), a variant of invasive lobular carcinoma (ILC) is described as an aggressive tumor with poor prognosis. Multiple studies show lower overall survival for patients with PLC than for patients with classic ILC (cILC). We compared the clinicopathologic characteristics of PLC with those of cILC. All cases with a diagnosis of ILC, Nottingham grades 2 or 3 that were diagnosed between January 1, 1990, and December 31, 2010, were retrieved from pathology files in the institutional anatomic pathology database. The cases (N = 52) were reviewed to identify those meeting the criteria for PLC. An E-cadherin immunostain was used to confirm the lobular immunophenotype. Clinicopathologic data were assessed and analyzed. A control group (N = 103) of cILC, Nottingham grade 1, was selected, with 2 controls for each case, matched by age and year of diagnosis. PLC was associated more closely with in situ carcinoma (P = .03), and had lower progesterone receptor expression (P = .03) than cILC. Both disease-free survival and overall survival were similar between patients with PLC and matched cILC controls, and both depended on disease stage, tumor size, and lymph node status. PLC is similar to cILC in terms of patient survival and outcomes.

Pleomorphic lobular carcinoma in situ of the breast: Can the evidence guide practice?

The clinical significance of pleomorphic lobular carcinoma in situ (PLCIS) is a subject of controversy. As a consequence, there is a risk of providing inconsistent management to patients presenting with PLCIS. This review aims to establish whether the current guidelines for the management of PLCIS are consistent with current evidence. A systematic electronic search was performed to identify all English language articles regarding PLCIS management. The data was analysed, specifically looking at: incidence of concurrent disease, recurrence rates, long-term prognosis and PLCIS management. A search was also performed for PLCIS management guidelines for the United Kingdom, United States, Canada, Australia, Germany and pan-European. The results of the evidence analyses were compared to the guidelines in order to establish whether the recommended management is consistent with the published evidence. Nine studies (level 3-4 evidence), involving a total of 176 patients and five management guidelines (from United Kingdom, United States, Australia and pan-European) were included in the review. From the evidence, 46 of 93 (49%) patients were found to have PLCIS with concurrent invasive disease on excision specimen analysis. Regarding recurrence rates, 11 of 117 (9.4%) patients developed a recurrence of PLCIS. There were no instances of invasive disease or ductal carcinoma in situ (DCIS) on recurrence histology. There were no studies assessing long-term outcomes in PLCIS cases. With regards to the management guidelines, the Association of Breast Surgery (United Kingdom) and the National Breast and Ovarian Cancer Care (Australia) do not mention PLCIS. The National Comprehensive Cancer Network (United States) suggest considering excision of PLCIS with negative margins. The NHS Breast Screening Programme (United Kingdom) and the European Society of Medical Oncology (pan-European) recommend PLCIS should be treated as with DCIS. We conclude that high quality evidence to inform guidance is lacking, thus recommendations are relatively vague. However, based on the available evidence, it would seem prudent to treat PLCIS in a similar manner to DCIS.

Lobular neoplasia

Lobular neoplasia (LN) is characterized by a dysfunctional E-cadherin-catenin axis, and loss of E-cadherin plays a causative role in the typical morphology of LN cells. LN is both a nonobligate precursor and a risk indicator of invasive breast cancer, and in particular, of invasive lobular carcinoma. Despite the evidence supporting the precursor role of LN, its impact on clinical management has been a matter of controversy, and conservative management remains the mainstay of treatment. In this article, an update is provided on the pathology and genetics of LN, and the management of these lesions in surgical practice is discussed.

When is excision necessary for atypical lobular hyperplasia and lobular carcinoma in situ?

SUMMARY This management perspective briefly covers the histology and molecular features of lobular in situ neoplasia and provides an in-depth discussion of the need for surgical excision if lobular in situ neoplasia is diagnosed on core-needle biopsy. The management of lobular in situ neoplasia found on core-needle biopsy has been an area of recent study with varying results. Emerging data suggest that low-risk patients with a limited extent of isolated classic lobular in situ neoplasia found on core-needle biopsy may not require subsequent surgical excision. However, high-risk patients, those with extensive lobular in situ neoplasia, or other high-risk lesions noted on core-needle biopsy likely benefit from surgical excision. Most authors recommend surgical excision when pleomorphic lobular carcinoma in situ is found on core-needle biopsy due to its higher association with invasive carcinoma. However, the natural history of this more recently described variant of lobular carcinoma in situ is not fully defined, and the clinical management of pleomorphic lobular carcinoma in situ on excisional biopsy is yet to be determined.

Pleomorphic lobular carcinoma of the breast: a morphologically and clinically distinct variant of lobular carcinoma

Pleomorphic lobular carcinoma is an uncommon variant of lobular carcinoma, characterized by significant cytologic atypia that contrasts with the low pleomorphism of classical lobular carcinoma. It accounts for approximately 1% of all epithelial breast malignancies. In addition to its pleomorphism, it is characterized by aggressive behavior and shortened patient survival. Although the morphologic features of pleomorphic lobular carcinoma are well described, it often eludes accurate pathologic characterization. Some controversy surrounds the pathogenesis of pleomorphic lobular carcinoma; however, it is now considered a well-defined variant of invasive lobular carcinoma. Pleomorphic lobular carcinoma shares molecular alterations with classical lobular carcinoma, such as alterations in the gene CDH1 on chromosome band 16q22 that results in changes in E-cadherin protein function. The aggressive biology of pleomorphic lobular carcinoma relates to the acquisition of genetic alterations typical of high-grade ductal carcinoma, such as overexpression of HER2/neu and c-myc.

Pleomorphic lobular carcinoma in situ

SUMMARY Pleomorphic lobular carcinoma in situ (PLCIS), the cytologic in situ correlate of invasive pleomorphic carcinoma (iPLC), was first recognized as an entity in 2002; however, previous descriptions of in situ lesions in association with iPLC were made in 1992. Recognition of the pleomorphic subtype of lobular carcinoma in situ is important because the combination of cellular features, necrosis and calcification can lead to difficulty in differentiating it from ductal carcinoma in situ and classic lobular carcinoma in situ, lesions for which standard treatment algorithms are supported by data regarding their natural history and risk of subsequent cancer. This article addresses the histological and molecular features that distinguish PLCIS from classic lobular carcinoma in situ and other variants of lobular neoplasia, describes the relationship between PLCIS and iPLC, reviews current challenges in the clinical management of PLCIS and provides a framework for future investigation.

Pleomorphic lobular carcinoma of the breast: is it a prognostically significant pathological subtype independent of histological grade?

Pleomorphic lobular carcinoma is regarded as a biologically aggressive variant of invasive lobular carcinoma of the breast. However, there is no consensus on the definition and whether this subtype adds useful information to histological grade. Two-hundred and two grade 2 or grade 3 invasive lobular carcinomas were studied. Tumours were categorised according to the components of histological grade: tubules, pleomorphism and mitoses. Pleomorphic lobular carcinoma was defined as a carcinoma with a lobular growth pattern and marked nuclear pleomorphism (pleomorphism 3). Breast cancer-specific survival was used in analysis of prognosis. Grade 3 pleomorphic lobular carcinomas (tubules 3, pleomorphism 3, mitoses 2 and tubules 3, pleomorphism 3, mitoses 3) had a worse prognosis than grade 2 (tubules 3, pleomorphism 2, mitoses 1) carcinomas. Grade 2 lobular carcinomas with marked nuclear pleomorphism (tubules 3, pleomorphism 3, mitoses 1) had a similar prognosis to grade 2 carcinomas with moderate pleomorphism (tubules 3, pleomorphism 2, mitoses 1). Survival was associated with mitotic score, but not with nuclear pleomorphism on both univariate and multivariate analysis. A non-classical growth pattern was seen more frequently in all subgroups with marked nuclear pleomorphism and was associated with worse survival. Histological grade and nodal status were independent of prognostic factors. This study shows that histological grade (in particular the mitotic component) in invasive lobular carcinomas is of prognostic importance, but pleomorphic type does not provide useful additional prognostic information.

[Pleomorphic lobular intraepithelial neoplasia: clinical, histological and prognostic study of nine cases]

INTRODUCTION

Retrospective clinical, histological and prognostic study of nine cases of lobular intraepithelial neoplasia in its pleomorphic subtype (LIN-P).

PATIENTS AND METHODS

Analysis of our center database with selection of nine cases of LIN-P from 140 files of patients who underwent surgical excision with a final diagnosis of LIN (2000 to 2011). The medical files were reviewed with a re-analysis of the mammograms and the histological slides. The outcome of the patients was also analyzed according to their clinical and operative data.

RESULTS AND DISCUSSION

The average age at diagnosis was 63 years (later than common LIN [LIN-C]). All patients had mammograms classified ACR 4 and 5, mainly due to the presence of microcalcifications (seven cases) with a case of opacity associated with microcalcifications, and two other cases with only isolated opacities. The preoperative diagnosis of these lesions was difficult: five cases on nine core needle biopsies were reviewed and reclassified LIN-P after finding the presence of LIN-P on the surgical specimen. Associated invasive lesions were found in 55% of core needle biopsy and in 33% of cases of surgical resection specimen. The treatment included a wide surgical excision (five lumpectomies and four mastectomies with a patient who had two lumpectomies) with margins of more than 2mm: we noted a recurrence of LIN-P only in one case where margins were very close (1mm). The analysis of our cases confirms that LIN-P if they probably share the same origin as the LIN-C represent a particular form constituting a true precancerous condition warranting at least a wide surgical excision.

Are the imaging features of the pleomorphic variant of invasive lobular carcinoma different from classic ILC of the breast?

The aim of this study was to evaluate whether pleomorphic invasive lobular carcinoma (PILC) is different from classic invasive lobular carcinoma (CILC) in terms of radiologic and clinicopathologic features. We compared the radiologic and clinicopathologic features of 22 surgically confirmed PILCs in 21 patients from 2004 to 2009 and 47 CILCs from 47 consecutive patients. For all cases, we reviewed the imaging findings, medical records and pathological results. PILC had a higher T stage, N stage, nuclear and histologic grade compared to CILC. PILC was more commonly negative for estrogen receptors and positive for HER2 than CILC (all p < 0.05). However, there were no significant differences in age, symptoms, tumor size, extensive intraductal component, lymphovascular invasion, triple negative profile, or multiplicity between the two groups. PILC was not detected on mammography in 1 (4.5%) of 22 cases, whereas CILC was not detected on mammography in 7 (14.9%) of 47 cases and on MRI in 2 (5.0%) of 40 (p = 0.42 and p = 1.000, respectively). MRI identified more frequent multiplicity than mammography for both PILC and CILC (p < 0.001), but was similar to US (p = 0.066). Most lesions showed a spiculated mass or architectural distortion with or without calcifications on mammography and ultrasound. No differences in mass and/or non-mass lesions or kinetics on MRI were observed between the two groups. PILC shows more pathologically aggressive features, but cannot be differentiated from CILC based on imaging findings.

Biologic characteristics of premalignant breast disease

Breast cancer is the second leading cause of cancer death in women in the United States. While mammography and breast magnetic resonance imaging (MRI) improve detection of early disease, there remains an unmet need for biomarkers for risk stratification, early detection, prediction, and disease prognosis. A number of early breast lesions, from atypical hyperplasias to carcinomas in situ, are associated with an increased risk of developing subsequent invasive breast carcinoma. The recent development of genomic, epigenomic, and proteomic tools for tissue biomarker detection, including array CGH, RNA expression microarrays, and proteomic arrays have identified a number of potential biomarkers that both identify patients at increased risk, as well as provided insights into the pathology of early breast cancer development. This chapter focuses on the detection and application of tissue and serum biomarkers for the identification and risk stratification of early breast cancer lesions.