The role of immunohistochemistry for smooth-muscle actin, p63, CD10 and cytokeratin 14 in the differential diagnosis of papillary lesions of the breast

Papillomatous breast lesions with atypical columnar cell features

AIMS

Columnar cell lesions (CCLs) are recognised breast cancer precursor lesions. Intraductal papillomas are usually lined by benign (polyclonal) cells. Although papillomas with monoclonal lesions (atypical ductal hyperplasia (ADH)/ductal carcinoma in situ (DCIS)) have been described, CCLs have not been described in papillomas.

METHODS

We present two papillary breast lesions lined by a single layer of luminal cells resembling atypical CCL/flat epithelial atypia (FEA). We compared these two lesions with 13 benign intraductal papillomas, and 2 papillomas with ADH/DCIS grade 1 features as controls were immunohistochemically stained for the oestrogen receptor alpha (oestrogen receptor) and progesterone receptors (PR), cytokeratin 5 (CK5) and cyclin D1.

RESULTS

Oestrogen receptor/PR expression was variable, with areas with ≥85% hormone receptor positivity in both morphologically normal papillomas and papillomas with ADH. In ADH areas, CK5 expression was seen in ≤5% of cells while cyclin D1 expression was high (>60%). The two papillary lesions with FEA were 100% oestrogen receptor and 90% cyclin D1 positive, and low on PR/CK5. There was only one morphologically normal papilloma with similar areas of low CK5 (5%) and high cyclin D1 expression; in all other morphologically benign papillomas CK5 expression varied between 10% and 50% and cyclin D1 expression was ≤50%. The papillary lesion with FEA that could be tested showed 16q losses, the hallmark genetic change in low nuclear grade breast neoplasias, in contrast to nine morphologically benign papillomas that could be tested.

CONCLUSION

We present two papillomatous breast lesions with atypical CCL morphology and 16q loss, for which we propose the term papillary FEA.

Knowledge of mucin immunostaining status of "nuclear inverse polarity papillary lesions lacking myoepithelial cells" may prevent unnecessary breast surgery: experience of two cases

We previously reported on two women with breast lesions in whom radiological examination could not exclude malignancy. In both cases, mastectomy was performed, and histological analyses revealed papillary lesions lined by fibrovascular stroma and nuclear inverse polarity. Hematoxylin-eosin, p63, and calponin staining indicated an absence of myoepithelial cells. However, it was concluded that the lesions had been non-malignant. These women have now been under long-term surveillance (74 months for one case and 62 months for the other) and have had no disease recurrence. Mucin (MUC)1, MUC2, MUC4, MUC5AC, MUC5B, and MUC6 immunostaining has also been performed in these women to investigate further whether their tumors were malignant or benign. In both cases, the tumors were only positive for MUC1 in apical luminal apical cells, as in normal breast tissue. MUC5B immunostaining, even when weak, can detect early breast cancer but was completely negative in our two cases. Therefore, both tumors were considered benign. Our findings in these cases suggest that nuclear inverse polarity papillary lesions lacking myoepithelial cells are benign. This knowledge should decrease the number of unnecessary operations performed for this tumor and their negative impact on patients' quality of life.

Dimorphic cells: a common feature throughout the low nuclear grade breast neoplasia spectrum

Columnar cell lesions (CCLs) are recognized precursor lesions of the low nuclear grade breast neoplasia family. CCLs are cystic enlarged terminal duct lobular units with monotonous (monoclonal) columnar-type luminal cells. CCLs without atypia are regarded as benign and CCLs with atypia as true precursor lesions with clonal molecular changes, a certain progression risk, and an association with more advanced lesions. However, reproducibility of designating atypia in CCL is not optimal, and no objective markers of atypia have been identified, although 16q loss seems to be associated with atypical CCLs. Dimorphic ("pale") cell populations have been described in low nuclear grade ductal carcinoma in situ (DCIS) but not in CCLs and atypical ductal hyperplasia (ADH). Therefore, we searched for pale cells in CCL (N = 60), ADH (N = 41), and DCIS grade 1 (N = 84). Diagnostic criteria were derived from the WHO, and atypia was designated according to the Schnitt criteria. Pale cells occurred in 0% (0/30), 73% (22/30), 56% (23/41), and 76% (64/84) of CCLs without atypia, CCLs with atypia, ADH, and DCIS grade 1, respectively. Pale cells expressed ERα, E-cadherin and p120 and variably cyclin D1, and lacked expression of CK5 and p63. In conclusion, dimorphic "pale" cells occur throughout the low nuclear grade progression spectrum, increasing in frequency with progression. Interestingly, CCL lesions without atypia do not seem to bear showed pale cells, indicating that the presence of pale cells may serve as a diagnostic morphological feature of atypia in CCLs.

Prognostic value of the immunohistochemical score based on four markers in head and neck squamous cell carcinoma

Purpose

Head and neck squamous cell carcinoma (HNSCC) ranks sixth among all cancers globally regarding morbidity, and it has a poor prognosis, high mortality, and highly aggressive properties. In this study, we established a model for predicting prognosis based on immunohistochemical (IHC) scores.

Methods

Data on 402 HNSCC cases were collected, the glmnet Cox proportional hazards model was used, risk factors were analyzed for predicting the prognosis of survival, and the IHC score was established. We used the IHC score to predict disease-free survival (DFS) using training and independent validation cohorts, including 264 cases in total. Additionally, the accuracy of the IHC score and the TNM system (8^th edition) was compared. A DFS prediction nomogram was established by combining the prognostic factors.

Results

The IHC scores included CK, Ki-67, p16, and p40 staining intensity. The concordance index and the Kaplan-Meier survival analysis showed that the IHC scores had high predictive power for HNSCC. Our results showed that the IHC score is an independent factor that can predict prognosis in a multivariate Cox regression analysis. When predicting DFS, the IHC score had a significantly higher value for the area under the ROC curve (AUC) than that of the TNM system. A nomogram was established and included the IHC score, age, tumor location, and the TNM stage. The calibration curves exhibited high consistency between the prognosis predicted by our nomogram and the actual prognosis.

Conclusions

The IHC score was more accurate than the eighth edition of the TNM system in predicting HNSCC prognosis. Therefore, combining the two methods can facilitate individualized patient consultation and care.

Papillary lesions of the breast - review and practical issues

Papillary lesions of the breast represent a heterogeneous group of neoplasm featuring fibrovascular cores covered by epithelial cells with or without intervening myoepithelial cells. According to the World Health Organization classification of breast tumors, papillary lesions of the breast are further classified into intraductal papilloma (including intraductal papilloma with atypical ductal hyperplasia /ductal carcinoma in situ), papillary ductal carcinoma in situ, encapsulated papillary carcinoma, solid papillary carcinoma (in situ and invasive) and invasive papillary carcinoma. The overlapping morphological features and immunohistochemical profiles make accurate diagnosis of breast papillary lesion a challenge for pathologists. In this review, the morphological and relevant immunohistochemical features of papillary lesions are discussed, with further emphasis on some commonly encountered practical diagnostic issues. A simple diagnostic algorithm will be established. The relevant molecular characteristics will be discussed as well.

Immunohistochemistry for diagnosis and prognosis of breast cancer: a review

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

Thymidylate Synthase, a New Myoepithelial Biomarker for Breast Lesions

Background. The identification of myoepithelial cells (MECs) can facilitate the differential diagnosis of breast lesions. We previously found thymidylate synthase (TS) expression in the nuclei of MECs in breast tissues, which prompted us to investigate the usefulness of TS as a sensitive and specific biomarker in the differential diagnosis of breast lesions, similar to other MEC biomarkers (ie, tumor protein [P63] and cluster of differentiation 10 [CD10]). Methods. Immunohistochemistry for TS, P63, and CD10 was performed on paraffin sections from 189 breast specimens. Results. The results showed the intensity of the immunoreactive TS signal to be comparable with that of P63 in the nuclei of MECs. Furthermore, the nuclei of MECs stained strongly for TS and P63 in normal breast tissues (obtained adjacent to invasive breast lesions), benign breast lesions, and carcinoma in situ, whereas the cytoplasm of MECs stained strongly for CD10. The immunoreactive TS signal in the cytoplasm of MECs was variable in 22 out of 32 (65.6%) cases of invasive breast carcinoma and 4 out of 20 cases (20.0%) of ductal carcinoma in situ. We found no immunoreactive TS signal in the nuclei of luminal and stromal cells in breast lesions, although there was a weak positive signal in the cytoplasm of luminal and stromal cells. Conclusions. TS is a sensitive and specific MEC biomarker in the differential diagnosis of breast lesions.

Utility of smooth muscle actin and CD117 as reliable markers in the diagnosis of salivary gland neoplasms

Objective:

The aim of this study is to analyze the utility of immunohistochemical markers such as CD117 and smooth muscle actin (SMA) in the diagnosis of various benign and malignant salivary gland neoplasms.

Materials and Methods:

The study comprises 17 samples categorized into three groups: Group I consisted of 5 histopathologically normal salivary gland tissue; Group II comprised 7 cases, of which 3 cases were pleomorphic adenoma, 3 cases were myoepithelioma and 1 case was Warthin's tumor; and Group III consisted of 5 cases, of which 1 was mucoepidermoid carcinoma and 4 cases were adenoid cystic carcinoma. The selected cases were subjected to immunohistochemistry (IHC) procedure to assess the expression pattern of CD117 and SMA.

Results:

In SMA, 85.8% showed severe-to-moderate intense expression among the tumor cells in benign salivary gland tumor. All the 5 malignant tumors showed the expression of SMA and 3 cases demonstrated severe expression among the tumor cells. An intense expression pattern of SMA was observed in both benign and malignant neoplasms in the periphery and stromal components of the tumor. Only two cases were positive for CD117, and connective tissue components were completely negative in both malignant and benign salivary gland neoplasms.

Conclusion:

Alpha-SMA can be utilized as reliable IHC markers for salivary gland neoplasms due to its diagnostic importance in tumors with myoepithelial origin indicative of the histogenesis of salivary gland tumors.

CXCL1 Derived from Mammary Fibroblasts Promotes Progression of Mammary Lesions to Invasive Carcinoma through CXCR2 Dependent Mechanisms

With improved screening methods, the numbers of abnormal breast lesions diagnosed in women have been increasing over time. However, it remains unclear whether these breast lesions will develop into invasive cancers. To more effectively predict the outcome of breast lesions and determine a more appropriate course of treatment, it is important to understand the underlying mechanisms that regulate progression of non-invasive lesions to invasive breast cancers. A hallmark of invasive breast cancers is the accumulation of fibroblasts. Fibroblast proliferation and activation in the mammary gland is in part regulated by the Transforming Growth Factor beta1 pathway (TGF-β). In animal models, TGF-β suppression of CCL2 and CXCL1 chemokine expression is associated with metastatic progression of mammary carcinomas. Here, we show that transgenic overexpression of the Polyoma middle T viral antigen in the mouse mammary gland of C57BL/6 mice results in slow growing non-invasive lesions that progress to invasive carcinomas in a stage dependent manner. Invasive carcinomas are associated with accumulation of fibroblasts that show decreased TGF-β expression and high levels of CXCL1, but not CCL2. Using co-transplant models, we show that decreased TGF-β signaling in fibroblasts contribute to mammary carcinoma progression through enhancement of CXCL1/CXCR2 dependent mechanisms. Using cell culture models, we show that CXCL1 mediated mammary carcinoma cell invasion through NF-κB, AKT, Stat3 and p42/44MAPK dependent mechanisms. These studies provide novel mechanistic insight into the progression of pre-invasive lesions and identify new stromal biomarkers, with important prognostic implications.

Use of immunohistochemical analysis of CK5/6, CK14, and CK34betaE12 in the differential diagnosis of solid papillary carcinoma in situ from intraductal papilloma with usual ductal hyperplasia of the breast

Objectives:

The aim of this study was to use immunohistochemistry to differentiate solid papillary carcinoma in situ from intraductal papilloma with usual ductal hyperplasia (IPUDH). Three types of high-molecular-weight cytokeratins (CKs) – CK5/6, CK14, and CK34betaE12 – were targeted.

Methods:

We studied 17 patients with solid papillary carcinoma in situ and 18 patients with IPUDH diagnosed by at least two pathologists. Immunohistochemical analyses used antibodies to CK5/6, CK14, and CK34betaE12 to make the differential diagnosis of solid papillary carcinoma in situ versus IPUDH. Immunohistochemical staining was scored as 0–5 using Allred score.

Results:

Immunohistochemistry with CK5/6 and CK14 antibodies produced scores of 0–3 in all patients with solid papillary carcinoma in situ and 2–5 in all patients with IPUDH. Immunohistochemical staining with CK34betaE12 antibody produced scores of 1–3 in all patients with solid papillary carcinoma and 3–5 in all patients with IPUDH. In tissues from patients with IPUDH, significantly more cells were stained with CK34betaE12 than CK5/6 (p < 0.05) or CK14 (p < 0.05).

Conclusion:

The immunoreactivity of CK5/6, CK14, and CK34betaE12 antibodies was useful to differentiate solid papillary carcinoma in situ from IPUDH. CK34betaE12 is especially useful for distinguishing solid papillary carcinoma from IPUDH.

Spatially correlated phenotyping reveals K5-positive luminal progenitor cells and p63-K5/14-positive stem cell-like cells in human breast epithelium

Understanding the mechanisms regulating human mammary epithelium requires knowledge of the cellular constituents of this tissue. Different and partially contradictory definitions and concepts describing the cellular hierarchy of mammary epithelium have been proposed, including our studies of keratins K5 and/or K14 as markers of progenitor cells. Furthermore, we and others have suggested that the p53 homolog p63 is a marker of human breast epithelial stem cells. In this investigation, we expand our previous studies by testing whether immunohistochemical staining with monospecific anti-keratin antibodies in combination with an antibody against the stem cell marker p63 might help refine the different morphologic phenotypes in normal breast epithelium. We used in situ multilabel staining for p63, different keratins, the myoepithelial marker smooth muscle actin (SMA), the estrogen receptor (ER), and Ki67 to dissect and quantify the cellular components of 16 normal pre- and postmenopausal human breast epithelial tissue samples at the single-cell level. Importantly, we confirm the existence of K5+ only cells and suggest that they, in contrast to the current view, are key luminal precursor cells from which K8/18+ progeny cells evolve. These cells are further modified by the expression of ER and Ki67. We have also identified a population of p63+K5+ cells that are only found in nipple ducts. Based on our findings, we propose a new concept of the cellular hierarchy of human breast epithelium, including K5 luminal lineage progenitors throughout the ductal-lobular axis and p63+K5+ progenitors confined to the nipple ducts.

Core Needle Biopsy of the Breast: An Evaluation of Contemporary Data

Benign and atypical lesions associated with breast cancer risk are often encountered in core needle biopsies (CNBs) of the breast. For these lesions, the rate of "upgrade" to carcinoma in excision specimens varies widely in the literature. Many CNB studies are limited by a lack of radiological-pathological correlation, consistent criteria for excision, and clinical follow-up for patients who forego excision. This article highlights contemporary diagnostic criteria and outcome data that would support an evidence-based approach to the management of these nonmalignant lesions of the breast diagnosed on CNB.

Papillary Lesions of the Breast: An Update

CONTEXT

-Papillary lesions of the breast, characterized by the presence of arborescent fibrovascular cores that support epithelial proliferation, constitute a heterogeneous group of neoplasms with overlapping clinical manifestation and histomorphologic features, but may have divergent biological behavior. These lesions are exclusively intraductal neoplasms, although an invasive carcinoma may rarely have a predominantly papillary architecture. Although recognition of a papillary architecture is typically not challenging, the histologic distinction of these entities is not always straightforward. Historically, different terminologies and variable criteria have been proposed for a given entity by various authorities. The difficulty in classifying these lesions has been further confounded by the scarcity of data and the heterogeneity across different studies with regard to the molecular genetic characteristics of this group of lesions.

OBJECTIVE

-To provide an overview focusing on the current concepts in the diagnosis and classification of papillary lesions of the breast incorporating recent molecular genetic advances.

DATA SOURCES

-Data were obtained from pertinent peer-reviewed English-language literature.

CONCLUSIONS

-The recent evolution of molecular techniques has enhanced our knowledge of the pathogenesis of papillary carcinomas of the breast. This, along with emerging outcome studies, has led to prognosis-based reclassification of some of these entities. Additional studies focusing on the molecular signatures are needed to identify potential decision tools to further stratify these lesions with respect to prognostic significance.

Pathological criteria and practical issues in papillary lesions of the breast - a review

Papillary lesions of the breast include a broad spectrum of lesions, ranging from benign papilloma, papilloma with atypical ductal hyperplasia (ADH) or ductal carcinoma in situ (DCIS) to papillary carcinoma. The accurate diagnosis of mammary papillary lesions is a challenge for pathologists, owing to the overlapping features among these lesions. In this review, some of the diagnostic criteria of papillary lesions are discussed, with special emphasis on some key morphological features, namely fibrovascular cores, epithelial proliferation in a solid pattern, intraductal papilloma complicated by ADH or DCIS, and invasion and its mimics. The roles of immunohistochemistry, and the interpretation of myoepithelial cell markers, hormone receptors, and high molecular weight cytokeratin, are addressed. Finally, novel biomarkers and genetic aberrations in papillary lesions are summarized.

Practical Considerations in Breast Papillary Lesions: A Review of the Literature

Context.—Diagnosis of papillary breast lesions, especially in core biopsies, is challenging for most pathologists, and these lesions pose problems for patient management. Distinction between benign, premalignant, and malignant components of papillary lesions is challenging, and the diagnosis of invasion is problematic in lesions that have circumscribed margins. Obtaining a balance between overtreatment and undertreatment of these lesions is also challenging.

Objectives.—To provide a classification and a description of the histologic and immunohistochemical features and the differential diagnosis of papillary breast lesions, to provide an update on the molecular pathology of papillary breast lesions, and to discuss the recommendations for further investigation and management of papillary breast lesions. This review provides a concise description of the histologic and immunohistochemical features of the different papillary lesions of the breast.

Data Sources.—The standard pathology text books on breast pathology and literature on papillary breast lesions were reviewed with the assistance of the PubMed database (http://www.ncbi.nlm.nih.gov/pubmed).

Conclusions.—Knowledge of the clinical presentation, histology, immunoprofile, and behavior of papillary breast lesions will assist pathologists with the diagnosis and optimal management of patients with papillary breast lesions.

Nipple adenoma in a female patient presenting with persistent erythema of the right nipple skin: case report, review of the literature, clinical implications, and relevancy to health care providers who evaluate and treat patients with dermatologic conditions of the breast skin

Background

Nipple adenoma is a very uncommon, benign proliferative process of lactiferous ducts of the nipple. Clinically, it often presents as a palpable nipple nodule, a visible nipple skin erosive lesion, and/or with discharge from the surface of the nipple skin, and is primarily seen in middle-aged women. Resultantly, nipple adenoma can clinically mimic the presentation of mammary Paget’s disease of the nipple. The purpose of our current case report is to present a comprehensive review of the available data on nipple adenoma, as well as provide useful information to health care providers (including dermatologists, breast health specialists, and other health care providers) who evaluate patients with dermatologic conditions of the breast skin for appropriately clinically recognizing, diagnosing, and treating patients with nipple adenoma.

Case presentation

Fifty-three year old Caucasian female presented with a one year history of erythema and induration of the skin of the inferior aspect of the right nipple/areolar region. Skin punch biopsies showed subareolar duct papillomatosis. The patient elected to undergo complete surgical excision with right central breast resection. Final histopathologic evaluation confirmed nipple adenoma. The patient is doing well 31 months after her definitive surgical therapy.

Conclusions

Since nipple adenoma represents a benign proliferative process of the nipple, complete surgical excision is curative. However, the coexistence of nipple adenoma and ipsilateral or contralateral breast cancer is well reported in the literature. The potential for a direct causal link or association of nipple adenoma and breast cancer cannot be fully excluded.

Application of Returned Cell Block Method (Cell Block from a Papanicolaou Staining Smear on a Glass Slide) for the Evaluation of Fine Needle Aspiration Cytology of Tumors of the Breast

BACKGROUND

In the fine needle aspiration cytology (FNAC) for tumors of the breast, evaluation is frequently difficult because of the thick-layered cell clusters and blood inclusion. Such problems may be resolved by the returned cell block method, but its use has not spread worldwide. Here, we examined the application of the returned cell block method to cases involving difficulty in the evaluation of FNAC to diagnose tumors of the breast.

METHODS

In Juntendo University Nerima Hospital, there were 22 cases which were difficult to diagnose by Papanicolaou stain only, and they underwent additional examination using the returned cell block method (cell block from a Papanicolaou staining smear on a glass slide). The usefulness of the returned cell block method in these cases was examined.

RESULTS

Among the 22 cases, a correct diagnosis was facilitated in 20 cases using the returned cell block method. In 16 of the 20 cases, the difficulty in FNAC was because of thick-layered cell clusters (12 cases) and blood inclusion (four cases). Among the 12 cases with difficulty because of the thick-layered cell clusters, 10 cases (83%) comprised intraductal papilloma (six cases) and intraductal papillary carcinoma (four cases). Papilloma and papillary carcinoma were correctly diagnosed by the addition of histological images and immunostaining of myoepithelial cells using the returned cell block method.

CONCLUSION

The application of the returned cell block method is useful for precise evaluation of the cytological diagnosis of tumors of the breast, especially papillary lesions. Diagn. Cytopathol. 2016;44:505-511. © 2016 The Authors Diagnostic Cytopathology Published by Wiley Periodicals, Inc.

Immunostaining of ∆Np63 (using the p40 antibody) is equal to that of p63 and CK5/6 in high-grade ductal carcinoma in situ of the breast

As a result of breast cancer screening programs, high-grade ductal carcinoma in situ (DCIS) of the breast is diagnosed more often. Frequently, a DCIS diagnosis can only be made using immunohistochemical stains to visualize the myoepithelial layer in order to assess microinvasion. Standard markers for myoepithelial cells are CK5/6 and p63. An isoform of the latter, ∆Np63, is recognized by a recently developed antibody, p40. Here, we compare the standard myoepithelial markers CK5/6 and p63 with p40. We immunostained full sections of tissue samples of 35 high-grade DCIS and compared the staining pattern of CK5/6, p63 and p40 in tumour tissue and in normal glands. Staining patterns of myoepithelial cells for p63 and p40 were similar in terms of the percentage of stained nuclei. In all cases, p63 was strongly expressed, while this was the case for p40 in 31 (89%) and moderately in 4 (11%) cases. All but one case (97%) showed a similar percentage of stained myoepithelial cells in comparing CK5/6 and p40 staining. CK5/6 expression was heterogeneous and strong/moderate/weak in 60, 34 and 6 % respectively. Compared to surrounding normal glands, staining of myoepithelial cells for all three markers in the neoplastic lesion was attenuated. In high-grade DCIS, p40 staining is highly specific for myoepithelial cells. Its staining pattern and intensity are equal to p63, which opens up its use for daily practice. Staining with p40 is less heterogeneous than that for CK5/6.

Application of immunohistochemistry in breast pathology: a review and update

CONTEXT

Immunohistochemistry is a valuable tool in routine breast pathology, used for both diagnostic and prognostic parameters. The diagnostic immunomarkers are the scope of this review. Most breast lesions can be diagnosed on routine hematoxylin-eosin sections; however, in several scenarios, such as morphologically equivocal cases or metastatic tumors of unknown primary, the appropriate application of immunohistochemistry adds true value in reaching an accurate diagnosis.

OBJECTIVE

To evaluate the diagnostic utility of the most commonly studied immunomarkers in the field of breast pathology by review of the literature, using the database of indexed articles in PubMed (US National Library of Medicine, Bethesda, Maryland) from 1976 to 2013.

DATA SOURCES

Literature review, and author's research data and personal practice experience.

CONCLUSIONS

The appropriate use of immunohistochemistry by applying a panel of immunomarkers and using a standardized technical and interpretational method will complement the morphologic assessment and aid in the accurate classification of difficult breast lesions and the identification of metastasis from a breast primary.

The significance of combined CK5/6 and p63 immunohistochemistry in predicting the risks of subsequent carcinoma development in intraductal papilloma of the breast

Prediction of subsequent risks of breast carcinoma (BC) development in intraductal papilloma (IDP) has remained controversial with the exception of atypical papilloma (AP). The potential value of immunohistochemistry (IHC) of cytokeratin 5/6 [CK5/6] and p63 have been proposed but its standardization has also remained controversial. We studied 17 patients initially diagnosed as IDP or AP who subsequently developed BC with 34 age-matched controls. We compared histological features, results of IHC (estrogen receptor [ER], progesterone receptor [PR], human epidermal growth factor receptor 2 [HER2], p63, CK5/6, Ki67), and ultrasound findings. Univariate conditional logistic regression analysis revealed that the status of both CK5/6 and p63/CK5/6 were significantly associated with subsequent BC development (P < 0.05). BC development in CK5/6 positive patients was 17.9% and p63/CK5/6 double positive patients 8.6%, respectively. Ultrasound evaluation was not significantly associated with any of the parameters examined and subsequent carcinoma development. Despite CK5/6 positivity, the subsequent incidence of BC development was nearly 20%. However p63/CK5/6 double positive status could predict a significantly lower subsequent carcinoma incidence, indicating a more accurate prognostic utility. Combining p63/CK5/6 with histological findings could be easily applied and could predict the subsequent BC development of the patients diagnosed as IDP at biopsy.

[Diagnostics of benign ductal epithelial cell proliferation of the breast in biopsy material]

The pathological evaluation of radiological or sonographical abnormalities by needle core biopsy of the breast frequently involves the differential diagnosis of benign epithelial cell proliferations. The lesions to be considered include usual type and atypical ductal epithelial cell hyperplasia, columnar cell changes including flat epithelial cell atypia, the spectrum of hyperplastic and atypical apocrine epithelial cell proliferations and papillary lesions. This review provides an overview of the diagnostic criteria, the current terminology and the differential diagnosis of these lesions. The clinical management and the prognosis of the lesions are discussed.

CD10-positive malignant spindle cell tumor of the lip in a child: a malignant myoepithelioma?

A 9-year-old girl consulted to our hospital because of lower lip tumor. Excision of the tumor was performed. Histologically, the tumor consisted of cellular spindle and round cells with hyperchromatic nuclei and nucleoli. Mitotic figure and apoptotic bodies were scattered. Immunohistochemically, the tumor cells were strongly and diffusely positive for CD10 and vimentin. The tumor was focally positive for S100 protein, α-smooth muscle actin, PDGFRA, HER2/neu, p53, and CD68. The Ki-67 labeling was 20%. In contrast, the tumor cells were negative for pancytokeratins (AE1/3, CAM5.2, WSS, KL-1, HNF116), cytokeratin (CK) 5/6, CK34βE12, CK7, CK8, CK14, CK18, CK19, CK20, EMA, desmin, CD34, melanosome, KIT, p63, myoglobin, CD45, CD56, GFAP, D2-40, CEA and synaptophysin. The Histologies, positive p53 protein, and Ki-67 labeling of 20% suggested low grade malignancy. Although histological type was unclear, the author diagnosed this tumor as malignant myoepithelioma arising from the lip minor salivary gland because of positive reaction for S100 protein, α-smooth muscle actin, and CD10. The patient is now free from tumor 8 years after the first presentation.

Histological analysis of benign breast imaging reporting and data system categories 4c and 5 breast lesions in imaging study

PURPOSE

The objective of this study was to analyze the histology of breast lesions categorized as Breast Imaging Reporting and Data System (BI-RADS) 4c or 5 breast lesions during the imaging evaluation, but diagnosed as benign during the histological evaluation.

MATERIALS AND METHODS

We retrospectively reviewed 71 breast lesions categorized as BI-RADS 4c or 5 during imaging study, but diagnosed as benign upon histological evaluation.

RESULTS

Breast lesions were classified into six groups upon histological analysis: intraductal papilloma (18 cases), inflammatory group (15 cases), fibroepithelial tumor (14 cases), clustered microcalcification (10 cases), minimal histological alteration (10 cases), and adenosis (4 cases). Sclerosis and architectural complexity were associated with most of the biopsies that were morphologically similar to malignancy.

CONCLUSION

Among 71 cases categorized as 4c or 5 during the imaging study, but diagnosed as benign upon histological examination, intraductal papilloma was the most frequently identified histological lesion. These 71 cases exhibited histological characteristics of sclerosis and/or complex/complicated features that should be histologically differentiated from malignancy during evaluation.

Myoepithelial cell differentiation markers in prepubertal bovine mammary gland: effect of ovariectomy

We reported previously that ovariectomy alters prepubertal development of mammary myoepithelial cells (MC) by mechanisms that are not well understood. Therefore, in the present study, we analyzed expression of 2 myoepithelial differentiation markers, α-smooth muscle actin (SMA) and the common acute lymphoblastic leukemia antigen (CD10), in mammary parenchymal tissue from intact (INT) and ovariectomized (OVX) heifers. On d 40, Holstein heifers underwent either an ovariectomy (OVX; n=16) or a sham (INT; n=21) operation. At 55, 70, 85, 100, 130, and 160 d of age, tissues were collected, and multispectral imaging was used to quantify immunofluorescent staining for myoepithelial cell (MC) markers. Fluorescent intensity (FI) of the markers was normalized against a control sample. In the basal epithelial layer, CD10 FI was less and SMA FI was greater in OVX than INT. The ratio of SMA to CD10 FI, as a proxy indicator for MC differentiation, was greater in tissue from OVX compared with INT heifers after 55 d of age. The staining for SMA was frequently more intense along the basal aspect of cells, whereas CD10 expression was localized on the apical surface of the MC. In mammary tissue from both INT and OVX heifers, we observed basal cells that were negative for both CD10 and SMA, some of which appeared to span the distance from basement membrane to the ductal lumen. Interestingly, we also observed CD10+ cells adjacent to the ductal lumen, a situation that was more prevalent in OVX than in INT heifers. Also, ovariectomy affects MC expression of both SMA and CD10, as well as the pattern of MC development. Myoepithelial cells are known to limit parenchymal growth in other species. Involvement of MC as regulators of prepubertal bovine mammary development is worthy of further investigation.

Combined evaluation of CK5/6, ER, p63, and MUC3 for distinguishing breast intraductal papilloma from ductal carcinoma in situ

The differentiation of intraductal papilloma (IDP) in the breast from ductal carcinoma in situ (DCIS) is sometimes difficult. Fifty papillary lesions (25 DCIS and 25 IDP) were immunohistochemically examined using a panel of antibodies, including CK5/6, ER, p63, Ki-67, chromogranin A, synaptophysin, neuron specific enolase, CD56, MUC1, MUC3, CD44, p21, p27, and p53. The immunohistochemical staining pattern of each antibody was evaluated using the Allred scoring system. Then, the area under curve (AUC) for each antibody was computed by receiver operating characteristic (ROC) analysis. DCIS typically showed high scores for ER and MUC3 reactivity compared with IDP, and the AUC for ER and MUC3 were 0.941 and 0.908, respectively. In contrast, IDP showed high scores for CK5/6 and p63 reactivity compared with DCIS, and the AUC for CK5/6 and p63 were 1.00 and 0.954, respectively. We devised a 'Differential Index' (DI) using the following formula: [S(ER) + S(MUC3)]/[S(CK5/6) + S(p63) + 1]. The distributions of the DI for IDP and DCIS did not overlap when the cutoff value was placed arbitrarily at DI = 1.0. From these results, it is concluded that a panel of four CK5/6, ER, p63, and MUC3 antibodies provide valuable information for differentiating IDP from DCIS.

Surgical excision of intraductal breast papilloma diagnosed on core biopsy

BACKGROUND

The need for surgical excision of benign papillary lesions diagnosed on core biopsy remains debatable. This lack of consensus arises because although there is a possibility of histological underestimation, there are as yet no reliable predictors of malignancy. We therefore aimed to evaluate the incidence of histological underestimation in our practice, and to identify factors that predict for this, in order to reduce unnecessary surgery without missing out on possible malignancy.

METHODS

Retrospective review of 106 patients diagnosed with a papillary lesion on percutaneous image-guided core biopsy was performed between 1 January 2005 and 31 December 2008. The presence of atypia on core biopsy and the presence of malignancy in the surgical specimen were correlated with standard clinical, radiological and pathological features.

RESULTS

Histological underestimation occurred in 15 of 81 patients (19%). Malignancy was more likely when atypia was present in the core biopsy (P= 0.04, OR 5.17). Otherwise, a final diagnosis of malignancy was not correlated with any clinical or radiological features (P > 0.05). The presence of atypia was also not correlated with any clinical or radiological features.

CONCLUSION

In our study, 19% of patients with a benign papillary lesion diagnosed on core biopsy were found to have atypical ductal hyperplasia or malignancy following surgery. In view of this, together with the absence of reliable predictive factors for malignancy, we recommend surgical excision of all papillary lesions diagnosed on core biopsy.

Luminal cytokeratin expression profiles of breast papillomas and papillary carcinomas and the utility of a cytokeratin 5/p63/cytokeratin 8/18 antibody cocktail in their distinction

Luminal cytokeratin (CK) expression in breast papillary lesions, and its potential diagnostic utility among other markers in distinguishing between papillomas and papillary carcinomas, has not been previously evaluated. Such expression was determined in 42 papillary lesions (18 papillary carcinomas and 24 papillomas) by immunostaining with a CK5/p63/CK8/18 antibody cocktail. The mean CK8/18 intensity score and percentage of positive cells were significantly higher in papillary carcinomas (227 and 95%, respectively, vs 86 and 42% in papillomas; both P-values <0.0001), whereas the mean CK5 intensity score and percentage of positive cells were significantly lower (7 and 5%, respectively, vs 107 and 58% in papillomas; both P-values <0.0001). Half (9/18) of the papillary carcinomas expressed p63 vs all (24/24) of the papillomas (P = 0.0001). P63 expression in papillary carcinoma was always (9/9; 100%) focal/limited in nature (expression in <10% of cells), whereas focal expression was seen in only four (17%) papillomas (P<0.0001). Both differential CK (CK8/18 and CK5) expression and p63 were equally sensitive (100%) for the diagnosis of papillary carcinoma, but differential CK expression was more specific (96 vs 83%), resulting in a greater accuracy. However, the best discriminatory power in the distinction from papilloma was achieved when all three markers were used in combination, resulting in 100% sensitivity and specificity values. It is concluded that breast papillary lesions have differential CK expression profiles that, especially in combination with p63, can be useful for their stratification, potentially also in needle biopsy material, in which more accurate and reproducible characterization is needed.

Myoepithelial Carcinoma: A Rare Neoplasm of the Breast

BACKGROUND: Malignant myoepitheliomas of the breast are extremely rare. There has been a limited number of published reports of myoepithelial carcinomas originating from the breast. CASE REPORT: We describe a malignant myoepithelioma of the breast in a 56-year-old woman. Histological examination showed polygonal epithelioid cells and spindle cells with moderate to marked nuclear atypia. Immunohistochemistry showed reactivity in the spindle cells for smooth muscle actin, cytokeratin (AE1/AE3), and p63, indicating a myoepithelial cell lineage of tumor cells. The patient underwent radical surgical excision of the lesion and axillary lymph node dissection. She demonstrated no evidence of recurrence over an 11-month follow-up. CONCLUSIONS: We suggest myoepithelial carcinomas of the breast be managed with appropriate surgical clearance. A multidisciplinary approach is usually required.

Epithelial displacement into the lymphovascular space can be seen in breast core needle biopsy specimens

Breast core needle biopsy (BCNB) has been reported to cause mechanical epithelial displacement into adjacent tissues, leading to diagnostic difficulties. However, epithelial displacement into lymphovascular spaces (EDLS), mimicking true lymphovascular invasion, may also be seen in the initial BCNB specimen itself. We retrospectively reviewed 218 BCNB specimens diagnosed as ductal carcinoma in situ (DCIS) and searched for the presence of EDLS. The subsequent surgically resected specimens for all cases were also reviewed. EDLS was demonstrated in 7 (3.2%) of 218 initial BCNB specimens. It could be differentiated from detached clusters of DCIS cells within preexisting ducts by morphologic features and immunohistochemical stains for D2-40 and p63. EDLS can occur at initial BCNB, and, therefore, the presence of tumor cell clusters within lymphovascular spaces in a BCNB specimen with DCIS may not represent true lymphovascular invasion.

Breast intracystic papillary carcinoma: an update

Intracystic papillary carcinoma (IPC), a breast tumor mainly occuring in the elderly, has long been considered as a variant of ductal carcinoma in situ (DCIS). This is now debated since metastatic cases have been reported. In this study, surgical pieces of 20 IPCs were reassessed, and markers of myopepithelial layer (p63, CD10 and Smooth Muscle Actin) as well as estrogen receptors (ER) and progesterone receptors (PgR) and C-erb-B2 oncoprotein expression were systematically performed and quantified. In 10 cases, an associated unequivocal invasive component was found. In all 20 cases, no myoepithelial layer was found. Eighteen tumors were ER positive, 14 were PgR positive. Moreover, none of the tumors over-expressed C-erb-B2 oncoprotein. Therefore this study showed that in all cases of IPC there were microscopic features of invasive carcinoma despite good clinical prognostic indicators, and that precise characterization of tumors requires extensive paraffin embedding of surgical pieces.

Effect of storage on p63 immunohistochemistry: a time-course study

One of the problems with immunohistochemistry is that storage of unstained slides can have a detectable negative effect on the intensity of staining for various antigens. This has not been well studied for the p63 antigen. A time-course study was performed to evaluate the effect of storage on the intensity of p63 immunohistochemical staining. Slides from various breast lesions/foci were stained with a p63 antibody on day 0 and after storage at room temperature for 2, 4, and 8 weeks. A p63 intensity score, ranging from 0 to 300, was calculated using the intensity (0, 1, 2, or 3+) and percentage of peripheral myoepithelial cell staining (0% to 100%). There was a progressive decline in the p63 intensity score with time with the differences between day 0 and 2 weeks and 2 and 4 weeks being statistically significant (P=0.037 and 0.001, respectively), whereas that between 4 and 8 weeks was not (P=0.075). These findings confirm a time-dependent decline in p63 immunostaining intensity evident as early as with 2 weeks of storage and still present after 8 weeks. This should be considered in the evaluation of p63 immunostains performed on stored unstained sections, both in diagnostic surgical pathology and in translational research studies.

The role of immunohistochemistry in the differential diagnosis of papillary lesions of the breast

Papillary lesions of the breast represent a heterogeneous group with differing biological behaviour. Correct diagnosis is crucial but may be difficult, as many benign and malignant papillary lesions have similar appearances. Immunohistochemistry plays a useful role in their differentiation. Myoepithelial markers can help in differentiating papilloma from papillary carcinoma, as the former usually shows a continuous layer of myoepithelial cells. In intracystic papillary carcinoma, there is controversy as to the presence of a complete myoepithelial cell layer around these lesions. p63 is the marker of choice as the staining is nuclear, cross-reactivity is minimal, and sensitivity is high. Papilloma may frequently be complicated by superimposed different types of epithelial hyperplasia, which range from usual to atypical or even ductal carcinoma in situ, and they many be morphologically similar. Basal cytokeratins (CKs) are useful to differentiate these entities; as usual hyperplasia is positive for basal CKs with a mosaic staining pattern. CK5/6 is probably the best marker. Neuroendocrine markers (chromogranin A and synaptophysin) may be positive in papillary carcinoma, particularly in the solid type, and there may be some overlap with the ductal carcinoma in situ with spindle cells or endocrine ductal carcinoma in situ. A panel of CK5/6, p63 and neuroendocrine markers can be useful in the diagnostic investigation of problematic papillary lesions of the breast. As the experience with these markers remains rather limited, it is too early to recommend basing treatment choices on these marker studies alone. Complete removal of lesion is probably still the treatment of choice.

Myoepithelial cells in solid variant of intraductal papillary carcinoma of the breast: a potential diagnostic pitfall and a proposal of an immunohistochemical panel in the differential diagnosis with intraductal papilloma with usual ductal hyperplasia

We examined myoepithelial status in intraductal papillary carcinoma (IPC) along with the expression of high-molecular weight cytokeratin (HMWK) and neuroendocrine markers, with special reference to the differential diagnosis of solid intraductal papillary carcinoma(SIPC) and intraductal papilloma with usual ductal hyperplasia (IP-UDH). Twenty-six (93%) of the twenty-eight intraductal papillomas (IP) had myoepithelial cells in >70% of the epithelial-stromal interface of the intraluminal proliferating component. Six (29%) of twenty-one SIPC had almost complete myoepithelial layer like IP-UDH at the epithelial-stromal interface. HMWK (34 beta E-12) was diffusely positive in 14 (93%) of 15 IP-UDH, but 16 (76%) of 21 SIPC were completely negative for HMWK. Neuroendocrine markers were positive in 14 (67%) of SIPC, but all 28 IPs were completely negative. If only the presence of myoepithelial cells is emphasized as a benign hallmark, about 30% of SIPCs may be underdiagnosed as IP-UDH. However, by using a combination of myoepithelial markers, HMWK, and neuroendocrine markers, all of the 36 solid intraductal papillary lesions were properly classified as benign and malignant. Solid intraductal papillary lesions meeting at least two of the following criteria are highly likely to be malignant: (1) absence of myoepithelial cells(<10% of epithelial-stromal interface of intraluminal proliferating component), (2) negative HMWK(<10%), (3) positive neuroendocrine markers (>10%).

[Multiple recurrent papillomas of the breast: case report]

We report the case of a patient presenting multiple recurrent papillomas of the breast. This mild mammary pathology, developed at the expense of the galactophoric ducts, recurred four times, in a nodular way, in spite of in sano surgical resection. The retrospective study of the cell proliferation and the DNA quantification of the cells constitutive of the papillomas, on several samples, underlined evolutive lesions, which could be predictive of a malignant degeneration. This observation allows us to discuss the management of this rare mild mammary pathology, which can sometimes lead to invasive breast carcinoma.