Apocrine Variant of Pleomorphic Lobular Carcinoma In Situ: Further Clinical, Histopathologic, Immunohistochemical, and Molecular Characterization of an Emerging Entity.

To date, the apocrine variant of lobular carcinoma in situ (AP-LCIS) has been cursorily described as a subtype of lobular carcinoma in situ (LCIS). We retrospectively reviewed 34 cases of AP-LCIS (including 23 associated with invasive lobular carcinoma) to fully characterize it. AP-LCIS typically presented with screen-detected calcifications in older women (mean age: 65 y) and was characterized by distended terminal duct lobular units with relatively large "pleomorphic" cells, central necrosis, and calcifications. AP-LCIS cells exhibited abundant eosinophilic occasionally granular cytoplasm, hyperchromatic nuclei, and prominent nucleoli. Synchronous classic and/or florid LCIS was identified in 24/34 (70%) AP-LCIS, and in 9/11 (82%) pure AP-LCIS. Most (68%) cases of AP-LCIS were estrogen receptor-positive (50% strongly), 35% were progesterone receptor-positive, 26% were human epidermal growth factor 2-positive, 18% demonstrated high-proliferation rate (Ki67: >15%), and 90% were androgen receptor-positive. Aurora kinase A, immunoreactive in 38% of AP-LCIS cases, was not significantly associated with recurrence, development of invasion, or nodal positivity (P>0.05). Compared with conventional (nonapocrine) pleomorphic lobular carcinoma in situ (P-LCIS), aurora kinase A was expressed in a significantly greater proportion of P-LCIS (100%). AP-LCIS and P-LCIS did not otherwise differ in clinicopathologic features. Next-generation sequencing utilizing the Oncomine Comprehensive Panel v2, performed on 27 AP-LCIS cases, showed no specific molecular findings. In a mean follow-up of 57 months, 2 (of 11, 18%) pure AP-LCIS cases recurred (2 both in situ and invasive) and none metastasized or proved fatal. AP-LCIS should be regarded as another high-grade LCIS similar to P-LCIS in many respects, and pending additional studies should be managed similarly.

Raman Spectroscopy Reveals That Biochemical Composition of Breast Microcalcifications Correlates with Histopathologic Features.

Breast microcalcifications are a common mammographic finding. Microcalcifications are considered suspicious signs of breast cancer and a breast biopsy is required, however, cancer is diagnosed in only a few patients. Reducing unnecessary biopsies and rapid characterization of breast microcalcifications are unmet clinical needs. In this study, 473 microcalcifications detected on breast biopsy specimens from 56 patients were characterized entirely by Raman mapping and confirmed by X-ray scattering. Microcalcifications from malignant samples were generally more homogeneous, more crystalline, and characterized by a less substituted crystal lattice compared with benign samples. There were significant differences in Raman features corresponding to the phosphate and carbonate bands between the benign and malignant groups. In addition to the heterogeneous composition, the presence of whitlockite specifically emerged as marker of benignity in benign microcalcifications. The whole Raman signature of each microcalcification was then used to build a classification model that distinguishes microcalcifications according to their overall biochemical composition. After validation, microcalcifications found in benign and malignant samples were correctly recognized with 93.5% sensitivity and 80.6% specificity. Finally, microcalcifications identified in malignant biopsies, but located outside the lesion, reported malignant features in 65% of in situ and 98% of invasive cancer cases, respectively, suggesting that the local microenvironment influences microcalcification features. This study confirms that the composition and structural features of microcalcifications correlate with breast pathology and indicates new diagnostic potentialities based on microcalcifications assessment. SIGNIFICANCE: Raman spectroscopy could be a quick and accurate diagnostic tool to precisely characterize and distinguish benign from malignant breast microcalcifications detected on mammography.

Breast carcinoma in sclerosing adenosis: a clinicopathological and immunophenotypical analysis on 206 lesions.

AIMS: To fully elucidate the clinicopathological features of breast carcinoma in sclerosing adenosis (SA-BC). METHODS: Clinical and histological characteristics of 206 SA-BCs from 180 patients were retrospectively evaluated. Immunohistochemical phenotype was examined. The clinicopathological relevance of the topographical pattern of SA-BCs was analysed. RESULTS: Overall, up to 46 patients (25.6%) had contralateral cancer, either SA associated or not. Of 99 cases who underwent core needle biopsy (CNB), 36 were underestimated as adenosis or atypical ductal hyperplasia at CNB, 5 invasive cases were misinterpreted as in situ carcinomas, whereas 4 ductal carcinoma in situ (DCIS) cases were overdiagnosed as invasive carcinoma. Microscopically, 163 tumours were in situ, including 136 DCIS, 19 lobular carcinomas in situ (LCIS) and 8 mixed DCIS/LCIS; of these carcinomas in situ (CIS), 37 had microinvasion. The DCIS group exhibited low, intermediate and high grades in 53.7%, 34.6% and 11.8% of cases, respectively, mostly with solid (43.4%) or cribriform (41.9%) pattern. Forty out of 43 invasive cases were invasive ductal carcinoma (IDC), mostly DCIS predominant. Immunophenotypically, luminal A phenotype was identified in 55.1%, 63.2% and 45.0% of DCIS, LCIS and IDC cases, respectively. Topographical type A group (carcinoma being entirely confined to SA, n=176) was characterised by smaller size, less invasiveness, lower grade and more frequency of luminal A immunophenotype compared with type B group (≥ 50% but not all of the carcinomatous lesion being located in SA, n=30) (all P<0.05). CONCLUSIONS: CIS, especially non-high-grade DCIS, represents the most common variant of SA-BC, and luminal A is the most predominant immunophenotype. CNB assessment might be challenging in some SA-BCs. The topographical pattern has great clinicopathological relevance. Careful evaluation of the contralateral breast and long-term follow-up for patients with SA-BC is necessary given its high prevalence of bilaterality.

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.

Mixed ductal-lobular carcinomas: evidence for progression from ductal to lobular morphology.

Mixed ductal-lobular carcinomas (MDLs) show both ductal and lobular morphology, and constitute an archetypal example of intratumoural morphological heterogeneity. The mechanisms underlying the coexistence of these different morphological entities are poorly understood, although theories include that these components either represent 'collision' of independent tumours or evolve from a common ancestor. We performed comprehensive clinicopathological analysis of a cohort of 82 MDLs, and found that: (1) MDLs more frequently coexist with ductal carcinoma in situ (DCIS) than with lobular carcinoma in situ (LCIS); (2) the E-cadherin-catenin complex was normal in the ductal component in 77.6% of tumours; and (3) in the lobular component, E-cadherin was almost always aberrantly located in the cytoplasm, in contrast to invasive lobular carcinoma (ILC), where E-cadherin is typically absent. Comparative genomic hybridization and multiregion whole exome sequencing of four representative cases revealed that all morphologically distinct components within an individual case were clonally related. The mutations identified varied between cases; those associated with a common clonal ancestry included BRCA2, TBX3, and TP53, whereas those associated with clonal divergence included CDH1 and ESR1. Together, these data support a model in which separate morphological components of MDLs arise from a common ancestor, and lobular morphology can arise via a ductal pathway of tumour progression. In MDLs that present with LCIS and DCIS, the clonal divergence probably occurs early, and is frequently associated with complete loss of E-cadherin expression, as in ILC, whereas, in the majority of MDLs, which present with DCIS but not LCIS, direct clonal divergence from the ductal to the lobular phenotype occurs late in tumour evolution, and is associated with aberrant expression of E-cadherin. The mechanisms driving the phenotypic change may involve E-cadherin-catenin complex deregulation, but are yet to be fully elucidated, as there is significant intertumoural heterogeneity, and each case may have a unique molecular mechanism. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

TIMP-3 mRNA expression levels positively correlates with levels of miR-21 in in situ BC and negatively in PR positive invasive BC.

BACKGROUND: Breast carcinomas (BC) belong to a heterogeneous group of malignant diseases. Correct categorization of BC based on molecular biomarkers has a very important role in deciding the proper course of therapy for each patient. It has been already shown that the decrease of TIMP metalloproteinase inhibitor 3 (TIMP-3) together with overexpression of microRNA-21 (miR-21) might be involved in the process of BC invasion. This is the first study that examined relationship among miR-21, TIMP-3 mRNA and TIPM-3 protein levels in BC groups formed according to invasiveness. METHODS: In this study, we used 46 breast cancer samples. Estrogen and progesterone receptor (ER, PR) protein levels were evaluated by immunohistochemistry (IHC) method. TIMP-3 mRNA expression was examined by two-step real-time quantitative PCR (qRT-PCR). Western blot analysis was performed for 16 samples. RESULTS: Statistically significant differences in TIMP-3 expression levels between invasive groups were discovered in ER positive (ER+) (p=0.015), Her-2 negative (p=0.026) subgroups, and patients without lymph-node metastasis (p=0.039). Interestingly, significant positive correlation was detected between miR-21 and TIMP-3 mRNA levels (P<0.001, ρ=0.949) in the group of in situ tumors. TIMP-3 mRNA expression levels highly negatively correlated with levels of miR-21 in PR+ invasive BCs (p=0.007, ρ=-0.641). TIMP-3 protein levels negatively correlated with miR-21 levels in pure invasive BCs. CONCLUSION: These data suggest that signaling pathways involved in formation and progression of BCs in groups formed according to invasiveness might be different. Our findings propose that TIMP-3 mRNA expression levels could be significant prognostic parameter, but within specific BC subtypes.

[Value of digital breast tomosynthesis (DBT) in the diagnosis of breast lesions].

Objective: To assess the value of digital breast tomosynthesis (DBT) in the diagnosis of breast lesions. Methods: Two hundred and fifty-three breast lesions in 250 patients were selected in this study. All lesions were confirmed pathologically. Preoperative diagnosis was performed independently with full-field digital mammography (FFDM), DBT and DBT plus FFDM, respectively. The diagnostic value of DBT for breast lesions was evaluated based on the pathological diagnosis as the gold standard. The diagnostic performance of DBT and FFDM for breast lesions was compared between the groups with different ages, mammary gland densities and hormone levels. The sensitivity of DBT and FFDM was compared between the groups with different pathological types and different sizes of breast cancer. The correlation between the longest diameter of breast cancers and pathological measurements shown on DBT and FFDM was analyzed. Results: The areas under ROC curves were 0.890, 0.833 and 0.890 for DBT, FFDM and DBT plus FFDM, respectively. The areas under ROC curves for DBT or DBT plus FFDM were significantly greater than that for FFDM (P<0.05). In the group with breast density>50%, group with age ≤50 and non-menopause group, all the areas under ROC curves for DBT or DBT plus FFDM were all significantly larger than that for FFDM (P<0.05). No significant differences were observed in the group with breast density ≤50%, group with age>50 and menopause group (P>0.05). The sensitivity for both DBT and FFDM in the diagnosis of carcinoma in situ was 90.9% (10/11). The sensitivity for DBT and FFDM in the diagnosis of non-carcinoma in situ was 92.3% (120/130) and 83.8% (109/130), respectively. The sensitivity in the groups with the longest diameter of foci >0 mm but ≤10 mm, >10 mm but ≤20 mm, >20 mm but ≤30 mm, and >30 mm but ≤40 mm were 51.7% (4/7), 93.8% (61/65), 96.7% (30/31) and 100% (11/11), respectively, for DBT, and were 51.7% (4/7), 78.5% (51/65), 93.5% (29/31), and 100% (11/11), respectively, for FFDM. The correlation coefficients between the longest diameter of breast cancers and pathological measurements shown on DBT and FFDM were 0.905 and 0.849, respectively (P<0.001). Conclusions: Compared with FFDM, DBT shows a higher diagnostic efficiency in patients with breast density >50%, age ≤50 years and non-menopause, non-carcinoma in situ, and the longest diameter of lesions >10 mm but ≤ 20 mm. The longest diameter of breast lesions is more accurately shown on DBT.

Pathological complete response in invasive breast cancer treated by skin sparing mastectomy and immediate reconstruction following neoadjuvant chemotherapy and radiation therapy: Comparison between immunohistochemical subtypes.

CONTEXT: Even if neoadjuvant chemotherapy (NACT) and oncoplastic techniques have increased the breast conserving surgery rate, mastectomy is still a standard for multifocal or extensive breast cancers (BC). In the prospect of increasing breast reconstruction, an alternative therapeutic protocol was developed combining NACT with neoadjuvant radiation therapy (NART), followed by mastectomy with immediate breast reconstruction (IBR). The oncological safety of this therapeutic plan still needs further exploration. We assessed pathological complete response (pCR) as a surrogate endpoint for disease free survival. METHODS: Between 2010 and 2016, 103 patients undergoing mastectomy after NACT and NART were recruited. After CT and RT were administrated, a completion mastectomy with IBR by latissimus dorsi flap was achieved 6 to 8 weeks later. pCR was defined by the absence of residual invasive disease in both nodes and breast. Histologic response was analyzed for each immunohistochemical subset. RESULTS: pCR was obtained for 53.4% of the patients. This pCR rate was higher in hormonal receptor negative (HER2 and triple negative) patients when compared to luminal tumours (69.7% vs 45.7%, p=0.023). DISCUSSION: The pCR rate found in this study is higher than those published in studies analyzing NACT (12.5%-27.1%). This can be explained by the combination of anthracycline and taxane, the use of trastuzumab when HER2 was overexpressed but also by RT associated to NACT. CONCLUSION: Inverting the sequence protocol for BC, requiring both CT and RT, allows more IBR without diminishing pCR and should therefore be considered as an acceptable therapeutic option.

Myoepithelial cells in lobular carcinoma in situ: distribution and immunophenotype.

Myoepithelial cells have important physical and paracrine roles in breast tissue development, maintenance, and tumor suppression. Recent molecular and immunohistochemical studies have demonstrated phenotypic alterations in ductal carcinoma in situ-associated myoepithelial cells. Although the relationship of lobular carcinoma in situ (LCIS) and myoepithelial cells was described in 1980, further characterization of LCIS-associated myoepithelial cells is lacking. We stained 27 breast specimens harboring abundant LCIS with antibodies to smooth muscle myosin heavy chain, smooth muscle actin, and calponin. Dual stains for E-cadherin/smooth muscle myosin heavy chain and CK7/p63 were also performed. In each case, the intensity and distribution of staining in LCIS-associated myoepithelial cells were compared with normal breast tissue on the same slide. In 78% of the cases, LCIS-associated myoepithelial cells demonstrated decreased staining intensity for one or more myoepithelial markers. The normal localization of myoepithelial cells (flat against the basement membrane, pattern N) was seen in 96% of LCIS, yet 85% of cases had areas with myoepithelial cell cytoplasm oriented perpendicular to the basement membrane (pattern P), and in 30% of cases, myoepithelial cells appeared focally admixed with LCIS cells (pattern C). This study characterizes detailed architectural and immunophenotypic alterations of LCIS-associated myoepithelial cells. The finding of variably diminished staining favors application of several myoepithelial immunostains in clinical practice. The interaction of LCIS with myoepithelial cells, especially in light of the perpendicular and central architectural arrangements, deserves further mechanistic investigation.