Breast lesions with myoepithelial phenotype.

Myoepithelial cells (MECs) constitute a continuous layer of cells surrounding the breast glands, localised between the epithelial cells (ECs) and the basal membrane. MECs play important roles in normal mammary gland as they produce basal membrane and stimulate secretion. During neoplastic transformation, MECs act as a barrier preventing stromal invasion. MECs themselves can undergo a great variety of changes, ranging from hyperplastic to metaplastic, to neoplastic, and giving rise to a wide spectrum of morphological pictures sometimes difficult to interpret on routine diagnoses. Several benign and malignant breast tumours can present features of MECs differentiation. As these latter tumours are quite infrequent, the purpose of the present study is to offer a review of the morphological spectrum of MECs lesions, with correlations to prognosis.

Which type of cancer is detected in breast screening programs? Review of the literature with focus on the most frequent histological features.

Breast cancer is the most frequent type of cancer affecting female patients. The introduction of breast cancer screening programs led to a substantial reduction of mortality from breast cancer. Nevertheless, doubts are being raised on the real efficacy of breast screening programs. The aim of the present paper is to review the main pathological type of cancers detected in breast cancer screening programs. Specifically, attention will be given to: in situ carcinoma, invasive carcinoma histotypes and interval cancer.

Post-radiotherapy vascular lesions of the breast: immunohistochemical and molecular features of 74 cases with long-term follow-up and literature review.

AIMS: A wide range of post-radiotherapy (RT) vascular lesions can occur, ranging from benign lymphangiomatous papules of the skin (BLAPs), to atypical vascular lesions (AVLs) and post-RT angiosarcomas (ASs). The relationship between benign and malignant post-RT breast lesions and their prognostic features are still controversial. The aims of this study were to investigate the relationship between benign and malignant mammary post-RT vascular lesions and to define post-RT AS prognostic features. METHODS AND RESULTS: Seventy-four post-RT vascular lesion cases were obtained and stained with antibodies against CD34, CD31, D2-40, Ki67, and c-Myc. Mutational analysis was performed by deep sequencing for the following genes: KRAS, NRAS, HRAS, BRAF, PIK3CA, TP53, NOTCH1, PTEN, CDKN2A, EGFR, AKT1, CTNNB1, hTERT, and PTPRB. Post-RT AS cases were graded according to a previously reported breast AS grading system. AVL cases showed a low number of HRAS and hTERT mutations, whereas post-RT AS cases showed a high frequency of EGFR, TP53, HRAS and hTERT mutations. On follow-up, all BLAP and AVL patients were alive with no evidence of disease. Post-RT AS 5-year overall survival declined with the increase in grade, as follows: 85.7% for grade 1, 83.3% for grade 2, and 40.4% for grade 3. CONCLUSIONS: Our findings confirm that BLAP and AVL have a good prognosis, and that post-RT AS prognosis is strongly related to histological grading. On molecular analysis, AVL and post-RT AS shared HRAS and hTERT mutations, suggesting a relationship between the two lesions.

Immunohistochemical assessment of HRAS Q61R mutations in breast adenomyoepitheliomas.

AIMS: Breast adenomyoepitheliomas (AMEs) are uncommon tumours. Most oestrogen receptor (ER)-positive AMEs have mutations in phosphoinositide 3-kinase (PI3K) pathway genes, whereas ER-negative AMEs usually harbour concurrent mutations affecting the HRAS Q61 hotspot and PI3K pathway genes. Here, we sought to determine the sensitivity and specificity of RAS Q61R immunohistochemical (IHC) analysis for detection of HRAS Q61R mutations in AMEs. METHODS AND RESULTS: Twenty-six AMEs (14 ER-positive; 12 ER-negative) previously subjected to massively parallel sequencing (n = 21) or Sanger sequencing (n = 5) of the HRAS Q61 hotspot locus were included in this study. All AMEs were subjected to IHC analysis with a monoclonal (SP174) RAS Q61R-specific antibody, in addition to detailed histopathological analysis. Nine ER-negative AMEs harboured HRAS mutations, including Q61R (n = 7) and Q61K (n = 2) mutations. Five of seven (71%) AMEs with HRAS Q61R mutations were immunohistochemically positive, whereas none of the AMEs lacking HRAS Q61R mutations (n = 17) were immunoreactive. RAS Q61R immunoreactivity was restricted to the myoepithelium in 80% (4/5) of cases, whereas one case showed immunoreactivity in both the epithelial component and the myoepithelial component. RAS Q61R immunohistochemically positive AMEs were associated with infiltrative borders (P < 0.001), necrosis (P < 0.01) and mitotic index in the epithelial (P < 0.05) and myoepithelial (P < 0.01) components. RAS Q61R IHC assessment did not reveal Q61K mutations (0/2). CONCLUSIONS: IHC analysis of RAS Q61R shows high specificity (100%) and moderate sensitivity (71%) for detection of HRAS Q61R mutations in breast AMEs, and appears not to detect HRAS Q61K mutations. IHC analysis of RAS Q61R may constitute a useful technique in the diagnostic workup of ER-negative AMEs.

Second International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions).

PURPOSE: The second International Consensus Conference on B3 lesions was held in Zurich, Switzerland, in March 2018, organized by the International Breast Ultrasound School to re-evaluate the consensus recommendations. METHODS: This study (1) evaluated how management recommendations of the first Zurich Consensus Conference of 2016 on B3 lesions had influenced daily practice and (2) reviewed current literature towards recommendations to biopsy. RESULTS: In 2018, the consensus recommendations for management of B3 lesions remained almost unchanged: For flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL) and radial scars (RS) diagnosed on core-needle biopsy (CNB) or vacuum-assisted biopsy (VAB), excision by VAB in preference to open surgery, and for atypical ductal hyperplasia (ADH) and phyllodes tumors (PT) diagnosed at VAB or CNB, first-line open surgical excision (OE) with follow-up surveillance imaging for 5 years. Analyzing the Database of the Swiss Minimally Invasive Breast Biopsies (MIBB) with more than 30,000 procedures recorded, there was a significant increase in recommending more frequent surveillance of LN [65% in 2018 vs. 51% in 2016 (p = 0.004)], FEA (72% in 2018 vs. 62% in 2016 (p = 0.005)), and PL [(76% in 2018 vs. 70% in 2016 (p = 0.04)] diagnosed on VAB. A trend to more frequent surveillance was also noted also for RS [77% in 2018 vs. 67% in 2016 (p = 0.07)]. CONCLUSIONS: Minimally invasive management of B3 lesions (except ADH and PT) with VAB continues to be appropriate as an alternative to first-line OE in most cases, but with more frequent surveillance, especially for LN.

Correction to: Second International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions).

The article Second International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions), written by Christoph J Rageth, Elizabeth AM O'Flynn, Katja Pinker, Rahel A Kubik-Huch, Alexander Mundinger, Thomas Decker, Christoph Tausch, Florian Dammann, Pascal A. Baltzer, Eva Maria Fallenberg, Maria P Foschini, Sophie Dellas, Michael Knauer, Caroline Malhaire, Martin Sonnenschein, Andreas Boos, Elisabeth Morris, Zsuzsanna Varga, was originally published electronically on the publisher's internet portal (currently SpringerLink) on November 30, 2018 without open access.

Reproducibility and predictive value of scoring stromal tumour infiltrating lymphocytes in triple-negative breast cancer: a multi-institutional study.

BACKGROUND: Several studies have demonstrated a prognostic role for stromal tumour infiltrating lymphocytes (sTILs) in triple-negative breast cancer (TNBC). The reproducibility of scoring sTILs is variable with potentially excellent concordance being achievable using a software tool. We examined agreement between breast pathologists across Europe scoring sTILs on H&E-stained sections without software, an approach that is easily applied in clinical practice. The association between sTILs and response to anthracycline-taxane NACT was also examined. METHODOLOGY: Pathologists from the European Working Group for Breast Screening Pathology scored sTILs in 84 slides from 75 TNBCs using the immune-oncology biomarker working group guidance in two circulations. There were 16 participants in the first and 19 in the second circulation. RESULTS: Moderate agreement was achieved for absolute sTILs scores (intraclass correlation coefficient (ICC) = 0.683, 95% CI 0.601-0.767, p-value < 0.001). Agreement was less when a 25% threshold was used (ICC 0.509, 95% CI 0.416-0.614, p-value < 0.001) and for lymphocyte predominant breast cancer (LPBC) (ICC 0.504, 95% CI 0.412-0.610, p-value < 0.001). Intra-observer agreement was strong for absolute sTIL values (Spearman ρ = 0.727); fair for sTILs ≥ 25% (κ = 0.53) and for LPBC (κ = 0.49), but poor for sTILs as 10% increments (κ = 0.24). Increasing sTILs was significantly associated with an increased likelihood of a pathological complete response (pCR) on multivariable analysis. CONCLUSION: Increasing sTILs in TNBCs improves the likelihood of a pCR. However, inter-observer agreement is such that H&E-based assessment is not sufficiently reproducible for clinical application. Other methodologies should be explored, but may be at the cost of ease of application.

Solid papillary breast carcinomas resembling the tall cell variant of papillary thyroid neoplasms (solid papillary carcinomas with reverse polarity) harbour recurrent mutations affecting IDH2 and PIK3CA: a validation cohort.

AIMS: Solid papillary breast carcinoma resembling the tall cell variant of papillary thyroid neoplasms (BPTC), also known as solid papillary carcinoma with reverse polarity, is a rare histological type of breast cancer that resembles morphologically the tall cell variant of papillary thyroid carcinoma. BPTCs are characterised by IDH2 R172 hotspot somatic mutations or mutually exclusive TET2 somatic mutations, concurrently with mutations affecting PI3K pathway-related genes. We sought to characterise their histology and investigate the frequency of IDH2 and PIK3CA mutations in an independent cohort of BPTCs, as well as in conventional solid papillary carcinomas (SPCs). METHODS AND RESULTS: Six BPTCs, not previously analysed molecularly, and 10 SPCs were reviewed centrally. Tumour DNA was extracted from microdissected histological sections and subjected to Sanger sequencing of the IDH2 R172 hotspot locus and exons 9 and 20 of PIK3CA. All six BPTCs were characterised by solid, papillary and follicular architecture with circumscribed, invasive tumour nodules composed of epithelial cells with reverse polarity. IDH2 mutations were identified in all six BPTCs (three R172S, two R172T and one R172G), four of which also harboured PIK3CA mutations (two H1047R, one Q546K and one Q546R). By contrast, all SPCs lacked IDH2 mutations, while one of 10 harboured a PIK3CA mutation (H1047R). CONCLUSION: We validated the presence of IDH2 R172 hotspot mutations and PIK3CA hotspot mutations in 100% and 67% BPTCs tested, respectively, and documented absence of IDH2 R172 mutations in SPCs. These findings confirm the genotypical-phenotypical correlation reported previously in BPTC, which constitutes an entity distinct from conventional SPC.

Invasion in breast lesions: the role of the epithelial-stroma barrier.

Despite the significant biological, behavioural and management differences between ductal carcinoma in situ (DCIS) and invasive carcinoma of the breast, they share many morphological and molecular similarities. Differentiation of these two different lesions in breast pathological diagnosis is based typically on the presence of an intact barrier between the malignant epithelial cells and stroma; namely, the myoepithelial cell (MEC) layer and surrounding basement membrane (BM). Despite being robust diagnostic criteria, the identification of MECs and BM to differentiate in-situ from invasive carcinoma is not always straightforward. The MEC layer around DCIS may be interrupted and/or show an altered immunoprofile. MECs may be absent in some benign locally infiltrative lesions such as microglandular adenosis and infiltrating epitheliosis, and occasionally in non-infiltrative conditions such as apocrine lesions, and in these contexts this does not denote malignancy or invasive disease with metastatic potential. MECs may also be absent around some malignant lesions such as some forms of papillary carcinoma, yet these behave in an indolent fashion akin to some DCIS. In Paget's disease, malignant mammary epithelial cells extend anteriorly from the ducts to infiltrate the epidermis of the nipple but do not typically infiltrate through the BM into the dermis. Conversely, BM-like material can be seen around invasive carcinoma cells and around metastatic tumour cell deposits. Here, we review the role of MECs and BM in breast pathology and highlight potential clinical implications. We advise caution in interpretation of MEC features in breast pathology and mindfulness of the substantive evidence base in the literature associated with behaviour and clinical outcome of lesions classified as benign on conventional morphological examination before changing classification to an invasive lesion on the sole basis of MEC characteristics.

A Noninvasive Test for MicroRNA Expression in Oral Squamous Cell Carcinoma.

MicroRNAs have recently been proposed as non-invasive biomarkers in Oral Squamous Cell Carcinoma (OSCC). The aim of this study was to analyze the expression of a panel of miRNAs in epithelial cells collected by oral brushing from OSCCs from regenerative areas after OSCC surgical resection and from their respective normal distant mucosa. Oral brushing specimens were collected from 24 healthy donors, 14 OSCC patients with specimens from tumour and normal distant mucosa, and from 13 patients who had OSCC resection, with samples from regenerative areas after OSCC resection and normal distant mucosa. Expression levels of eight targets (miR-21, miR-375, miR-345, miR-181b, miR-146a, miR-649, miR-518b, and miR-191) were evaluated by real-time Polymerase Chain Reaction (PCR). A highly significant between-group difference was found for miR-21 (F = 6.58, p < 0.001), miR-146a (F = 6.974, p < 0.001), and miR-191 (F = 17.07, p < 0.001). The major difference was observed between samples from healthy donors and from OSCC brushing, whereas no significant differences were observed between areas infiltrated by OSCC and their respective normal distant mucosa. Furthermore, altered expression of miR-146a and miR-191 was also observed in regenerative areas after OSCC resection. CONCLUSIONS: Oral brushing could be proposed as a noninvasive method to study microRNA expression in oral mucosa in OSCC patients.

Ultrastructural Examination of a Case of Pagetoid Bowen Disease Exhibiting Immunohistochemical Features in Common With Extramammary Paget Disease.

A panel of immunohistochemical markers may be used to differentiate between pagetoid Bowen disease (PBD) and primary extramammary Paget disease (EMPD) in selected cases. Although diffuse staining with cytokeratin 7 (CK7), CAM5.2, carcinoembryonic antigen, epithelial membrane antigen (EMA), and gross cystic disease fluid protein 15 generally supports diagnosis of EMPD, cases have been reported where PBD also expressed CK7, EMA, and CAM5.2. Based on these findings, some authors suggested that the 2 entities may arise from the same multipotent stem cell, capable of further differentiation toward squamous and secretory lines. To the best of our knowledge, this issue has never been investigated by comparing PBD and EMPD at the ultrastructural level. We performed the first ultrastructural study of a case of PBD exhibiting common immunohistochemical features with EMPD. The lesion displayed some ultrastructural features often observed in Bowen disease and some that are typically found in EMPD. These findings indicate the presence of a bidirectional differentiation--secretory and squamous--within the same lesion, thus supporting the hypothesis that PBD and primary EMPD may arise from a common progenitor cell.

PRAME Expression in Mucosal Melanoma of the Head and Neck Region.

PRAME (PReferentially expressed Antigen in MElanoma), a cancer-testis antigen expressed in normal and neoplastic tissues with several functions, proved to be a useful diagnostic tool in the differential diagnosis between benign and malignant melanocytic lesions. The current study aims to perform PRAME stain on a retrospective case series of mucosal melanocytic tumors of the head and neck region to compare 3 different scores and evaluate the most reliable one in this diagnostic set. Immunohistochemical analysis for PRAME was performed in 54 benign and malignant mucosal melanocytic tumors of the head and neck region collected from 41 patients. The best-performing cutoff of PRAME-positive cells (nuclear stain) to differentiate benign and malignant mucosal melanocytic tumors of the head and neck region is that proposed by Raghavan and colleagues (<60%/≥60% of PRAME-positive cells), with 100% and 77.8% of benign lesions and malignant tumors respectively correctly identified. Applying this score, PRAME stain showed the best results (sensitivity, specificity, accuracy, and positive and negative predictive values) for the diagnosis of head and neck melanocytic tumors. However, a subset of PRAME-negative malignant tumors was identified, especially located in the palatal area (hard and soft palate). Finally, high PRAME expression (≥60%) was associated with specific sites (nasal cavity/nasal septum/turbinates nasopharynx, and the maxillary sinus), nodular histotype, and female sex.

High-grade HER2-positive mucoepidermoid carcinoma of the breast: a case report and review of the literature.

BACKGROUND: Mucoepidermoid carcinoma of the breast is a rare special type of salivary gland-like tumor of the breast, usually displaying triple-negative phenotype. To date, only 64 cases have been reported in the English literature. Herein, we report the first case of mucoepidermoid carcinoma of the breast with human epidermal growth factor receptor 2 gene amplification. CASE PRESENTATION: A 58-year-old Caucasian woman treated with breast-conserving surgery, radiotherapy, and chemotherapy for an invasive breast carcinoma of no special type, relapsed 20 years later in the ipsilateral left breast. Histological examination of the core needle biopsy of the relapse deferred to the surgical specimen for the definitive diagnosis, because of the broad differential diagnosis. On the resected specimen we observed the presence of a poorly differentiated carcinoma with mucoepidermoid carcinoma of the breast typical features consisting of epidermoid, intermediate and mucinous cells lacking true keratinization, in keeping with the latest World Health Organization diagnostic criteria. The mucoepidermoid carcinoma of the breast was weakly estrogen receptor and androgen receptor positive and progesterone receptor negative, but exceptionally showed human epidermal growth factor receptor 2 gene amplification. Mastermind-like transcriptional coactivator 2 gene translocations were not detected by fluorescent in situ hybridization. The patient received adjuvant chemotherapy with anti-human epidermal growth factor receptor 2 therapy but no endocrine therapy. After 61 months of follow-up, no signs of local or distant recurrence were observed. CONCLUSIONS: Mucoepidermoid carcinoma of the breast is a very rare entity. Despite being most frequently triple negative, the standard evaluation of receptor status is mandatory, as well as strict application of World Health Organization diagnostic criteria for correct patient management.

Prognosis of Deantigenated Equine Bone Used for Bone Augmentation: A Multicenter Retrospective Study on Early and Late Postsurgical Complications in 81 Consecutive Patients.

PURPOSE: To evaluate the clinical outcome of deantigenated equine bone (DEB) grafts in a series of patients treated with DEB at six months postaugmentation. MATERIALS AND METHODS: One hundred DEB grafts were inserted in 81 patients between January 2004 and December 2006. Thirty-two DEBs were blocks and 68 were granules (52 sinus lift and 16 guided bone regeneration [GBR] procedures performed). A total of 147 implants were inserted. A Pearson chi-square test was used to detect any statistically significant correlation between the studied variables and early and/or late failures. RESULTS: There were 6 early and 26 late graft failures and another 16 failures after prosthesis placement. The overall failure rate was 25% in the GBR procedures, 31.9% in sinus lift, and 54.3% with blocks, for a total complication rate of 39.5%. A statistically significant relation was detected with respect to graft type and early complications (p = .005), with a worse outcome for DEB blocks compared to granules. After provisional prosthesis restoration, 23 implants were lost, and another 41 failed after definitive prosthesis delivery, for an overall failure rate of 43.5%. The follow-up period was 3 years after surgery. CONCLUSIONS: DEB grafting material had a very high rate of complications. Blocks had more than 50% failures, mainly in the immediate postoperative period. Other procedures such as GBR and sinus lift also showed more than 25% infections and resorption, and late failures (i.e., after-implant placement) were also common. Our results show that DEB is less than ideal for crestal bone reconstruction.

Cancerization of cutaneous flap reconstruction for oral squamous cell carcinoma: report of three cases studied with the mtDNA D-loop sequence analysis.

AIMS: Tissue defects, resulting from surgical resection of oral squamous cell carcinoma (OSCC), are reconstructed routinely with skin grafts. OSCC arising from the grafted skin has been described; however, it is still unclear whether primary and second tumours have a common clonal origin. The aim of this study was to evaluate the clonal relationship between the primary OSCC and secondary neoplastic changes appearing in the skin graft in three patients, by screening the mitochondrial DNA D-loop region (mtDNA). METHODS AND RESULTS: In all three cases, the neoplastic lesions arising in the skin graft showed a clonal relationship with the previous OSCC and, on the basis of the results obtained by mtDNA analysis, could be considered to be a recurrence of the primary OSCC rather than a second primary OSCC. CONCLUSIONS: Starting from a field of genetically altered cells in the oral mucosa, the spread of the clonal cell population to the cutaneous flap might be stimulated by cytokines produced by the grafted skin. More studies are needed to evaluate the molecular relationship between primary and second OSCC to identify patients at higher risk of developing a second tumour in the skin graft.

Ki-67 from clinically and histologically "normal" distant mucosa as prognostic marker in early-stage (T1-T2N0) oral squamous cell carcinoma: a prospective study.

PURPOSE: The aggressive behavior and long-term prognosis of oral squamous cell carcinoma (OSCC) have recently been related to the mucosa surrounding the primary mass, consisting of genetically altered cells that might be responsible for cancer progression. Early-stage T1-T2N0 OSCCs have been associated with a good prognosis; however, a certain percentage of them can be complicated by locoregional metastases. The purpose of our study was to determine whether an abnormal proliferative status can be found in clinically and histologically "normal" mucosa situated in areas distant from the primary tumor. We also sought to determine whether this is associated with a poor prognosis in terms of local recurrence or lymph node metastasis. PATIENTS AND METHODS: The prospective study included 42 consecutive patients with T1N0M0 (n = 19) and T2N0M0 (n = 23) OSCC. Disease-free survival endpoints were defined as the duration between surgical resection and the diagnosis of recurrence, lymph node metastasis, or last follow-up visit. Proliferative status in distant areas (opposite cheek) was evaluated by Ki-67 expression. RESULTS: The mean Ki-67 value (17.6% ± 8.2%) in the distant mucosa was significantly greater (F = 13.87; P < .01) than that found in the controls (9.8 ± 3.1). "Abnormally high" Ki-67 values were detected in 13 patients with OSCC (30%). Four patients developed locoregional recurrence during follow-up. Kaplan-Meier analysis showed that Ki-67 in the distant mucosa was a significant independent prognostic factor for disease-free survival. CONCLUSIONS: A certain percentage of patients surgically treated for early T1-T2 OSCC will have an abnormal proliferative status in areas very distant from the primary tumor that seems to be related to a poor prognosis.

Hormone Receptor Expression Variations in Normal Breast Tissue: Preliminary Results of a Prospective Observational Study.

Normal breast tissue undergoes great variations during a woman's life as a consequence of the different hormonal stimulation. The purpose of the present study was to examine the hormonal receptor expression variations according to age, menstrual cycle, menopausal state and body mass index. To this purpose, 49 tissue samples of normal breast tissue, obtained during surgery performed for benign and malignant conditions, were immunostained with Estrogen (ER), Progesterone (PR) and Androgen receptors (AR). In addition, Ki67 and Gross Cystic Disease Fluid Protein were studied. The data obtained revealed a great variability of hormone receptor expression. ER and AR generally increased in older and post-menopausal women, while young women presented a higher proliferative rate, evaluated with Ki67. PR increase was observed in women with BMI higher than 25. The different hormonal receptor expression could favor the development of breast cancer.

Hemorrhagic Schwannoma of the Cauda Equina: Case Report and Review of the Literature.

Spinal intradural hemorrhage is a rare event; the most common causes of spinal bleeding are traumas, medical therapy with anticoagulants and thrombolytics, vascular malformations, and congenital defects of coagulation. Rarely, spinal cord tumors may cause hemorrhage. Herein, we report the case of a patient with acute and quickly worsening lumbar pain: the neurological examination revealed a flaccid paraplegia caused by an intradural lesion extending on the right side of the spinal cord from T1 to L2 vertebral level. Pathological examination revealed an hemorrhagic schwannoma. Acute spinal subdural hemorrhage caused by spinal schwannomas is a very rare occurrence (29 cases only have been previously reported). Review of the literature with clinico-diagnostic features is presented, surgical treatment is explained, and pathological findings with possible etiopathogenesis of hemorrhage are described.

NGS-based miRNome identifies miR-449 cluster as marker of malignant transformation of sinonasal inverted papilloma.

OBJECTIVE: identification of the miRNA expression profile in sinonasal inverted papilloma (SNIP) as a tool to evaluate the risk of transformation into sinonasal squamous cell carcinoma (SNSCC). MATERIALS AND METHODS: paired tumour tissues and adjacent normal tissues were obtained from SNIP and SNSCC patients who had undergone surgical resection and used for next-generation sequencing (NGS)-based miRNome analysis. SNIP tissues with concomitant dysplasia (SNIP-DISP) were used as malignant transition samples. By comparing the deregulated miRNAs in SNIP and SNSCC, an miRNA cluster was identified and its physio- and clinical-pathological value was predicted. RESULTS: NGS identified 54 miRNAs significantly down- and upregulated in SNIP. Among them, the miR-449 cluster was upregulated in SNIP and could differentiate the benign tumour from normal tissue. Notably, the miR-449 cluster was found to be significantly underexpressed in SNSCC, and the cluster markedly changed in SNIP during the malignant transition into SNSCC. miRNA enrichment analysis and GO analysis revealed that miR-449 is involved in apoptotic and cell proliferation pathways. CONCLUSIONS: Our findings suggest that miR-449 may be involved in the molecular pathogenesis of SNIP and its malignant transformation into SNSCC. miR-449 might therefore be a useful tumour biomarker in patients with SNIP and may also have the potential to be used as a tool for detecting and monitoring the course of the possible malignant transformation.

Chromosome X aneusomy and androgen receptor gene copy number aberrations in apocrine carcinoma of the breast.

Carcinomas with apocrine differentiation (CAD) of the breast are rare tumours typically presenting high immunohistochemical expression of androgen receptor (AR) which is a target molecule for personalised therapy. To date, no studies have evaluated the genetic changes that are associated with AR immunohistochemical expression in CADs. The present work aims to characterise AR status in CADs. Twenty CAD tumours were studied with immunohistochemistry, in situ fluorescence hybridization and DNA methylation analysis, to evaluate AR expression and its regulator status. All tumours demonstrated high AR immunohistochemical expression, with over 95% of the neoplastic cells showing AR positivity in 19/20 cases. CADs showed AR gene copy loss in a percentage of neoplastic cells ranging from 5 to 84% (mean 48.93%). AR regulator genes, including the MAGE family, UXT and FLNA, presented variable methylation levels, but were mainly hypomethylated and therefore all transcriptionally active. The results of this study indicate that CADs present AR monosomy, paralleled by higher transcriptional activity of the gene with potential to influence response to AR deprivation therapy.