Use of immunohistochemistry in diagnosis of breast epithelial lesions

Merkel cell carcinoma, melanoma, metastatic mimics of breast cancer

Merkel cell carcinoma and melanoma can each occur primarily in breast skin, or metastasize to the breast. The breast is a rare site of metastasis of essentially any and every type of tumor, including carcinomas, sarcomas, and hematolymphoid neoplasms, and 10-30% of breast metastases may represent the initial presentation of disease. Although metastases generally recapitulate histologic features of the primary tumor, they are diagnostically challenging given their rarity and morphologic overlap with breast carcinoma, including special types of breast cancer. Histologic clues may include lack of carcinoma in situ, lack of central elastosis, pattern of infiltration around normal breast structures, yet none of these are specific. Careful correlation with clinical history and judicious use of immunostain panels is essential in approaching these cases.

Pseudoangiomatous Stromal Hyperplasia in Core Needle Biopsies of Breast Specimens

BACKGROUND

Pseudoangiomatous stromal hyperplasia (PASH) is a benign lesion of myofibroblasts that is composed of a network of slit-like channels that resemble vascular spaces. The aims of this study were to document the frequency of PASH in core needle biopsy specimens (CNBS) of the breast, to describe which histopathologic findings coexist with PASH and to examine any endothelial cell differentiation.

MATERIALS AND METHODS

We reevaluated hematoxylin and eosin-stained sections of all CNBS that were obtained during a 1-year period. First, we performed CD34 and CD31 immunostainings to highlight the areas of PASH, then performed D2-40/podoplanin (lymphatic endothelial marker) and Fli-1 (vascular endothelial cell marker) immunostains.

RESULTS

The total number of CNBS was 412. Areas of PASH were noted in 37 of the 412 cases (9%), with a mean age of 38.5 years. The lesions that were described in association with PASH were "benign breast parenchyma with stromal fibrosis" (17/37; 46%), "fibroepithelial tumors" (17/37; 46%), "columnar cell changes (CCC)" (2/37; 5%), and "invasive carcinoma" (1/37; 3%). There were 2 cases of CCC within the foci of PASH (direct contact with PASH), and 8 additional cases of CCC that coexisted in the same specimen but were not in direct contact. There was no staining for D2-40 or Fli-1 within PASH foci.

CONCLUSION

PASH lesions occurred with a frequency of 9% in CNBS and were mostly in association with benign breast lesions in premenopausal women. CCC was determined as an accompanying epithelial lesion within or near PASH areas. No obvious immunopositivity compatible with endothelial cell differentiation was revealed.

Metastases to nasal cavity and paranasal sinuses

The sinonasal cavities are rare locations for metastases. Metastases to these locations are usually solitary and produce similar symptoms to those of a primary sinonasal tumor. Nasal obstruction and epistaxis are the most frequent symptoms. The maxillary sinus is most frequently involved. The most common primary tumor sites to spread to this region originate in the kidney, breast, thyroid, and prostate, although any malignancy could potentially lead to a metastasis to the paranasal sinuses. The patient's prognosis is usually poor because of the fact that the sinonasal metastasis is usually associated with widespread disseminated disease. In the majority of patients, palliative therapy is the only possible treatment option. Nevertheless, whenever possible, surgical excision either alone or combined with radiotherapy may be useful for palliation of symptoms and, rarely, to achieve prolonged survival. This review considers the most interesting cases reported in the literature that presents metastases to the sinonasal cavities. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1847-1854, 2016.

Use of Immunohistochemical Stains in Epithelial Lesions of the Breast

BACKGROUND

During the last few decades, immunohistochemistry (IHC) has become an integral part of pathology. Although hematoxylin and eosin (H & E) stain remains the fundamental basis for diagnostic pathology of the breast, IHC stains provide useful and sometimes vital information. Moreover, considering the role of hormonal therapy in hormone receptor-positive breast tumors, as well as the availability of targeted chemotherapeutic agents for HER2-positive cases, IHC studies represent a major part of workups.

METHODS

A literature search was performed to explore the uses of IHC stains related to the diagnoses of breast lesions and prognostic/predictive information.

RESULTS

Selective use of IHC stains in conjunction with H & E examination helps resolve most diagnostic issues encountered by surgical pathologists during their day-to-day practice. Pathologists should be familiar with the use of each immunostain and its limitations to avoid interpretative errors.

CONCLUSIONS

IHC stains help guide the differential diagnosis of challenging epithelial lesions of the breast. They should be selectively and judiciously used and their findings must be interpreted with the differential diagnoses in mind and with an understanding of possible pitfalls.

Cervical lymph node metastases from remote primary tumor sites

Although most malignant lymphadenopathy in the neck represent lymphomas or metastases from head and neck primary tumors, occasionally, metastatic disease from remote, usually infraclavicular, sites presents as cervical lymphadenopathy with or without an obvious primary tumor. In general, these tumors metastasize to supraclavicular lymph nodes, but occasionally may present at an isolated higher neck level. A search for the primary tumor includes information gained by histology, immunohistochemistry, and evaluation of molecular markers that may be unique to the primary tumor site. In addition, 18F-fluoro-2-deoxyglocose positron emission tomography combined with CT (FDG-PET/CT) has greatly improved the ability to detect the location of an unknown primary tumor, particularly when in a remote location. Although cervical metastatic disease from a remote primary site is often incurable, there are situations in which meaningful survival can be achieved with appropriate local treatment. Management is quite complex and requires a truly multidisciplinary approach. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2374-E2385, 2016.

Myoepithelial cell differentiation markers in ductal carcinoma in situ progression

We describe a preclinical model that investigates progression of early-stage ductal carcinoma in situ (DCIS) and report that compromised myoepithelial cell differentiation occurs before transition to invasive disease. Human breast cancer MCF10DCIS.com cells were delivered into the mouse mammary teat by intraductal injection in the absence of surgical manipulations and accompanying wound-healing confounders. DCIS-like lesions developed throughout the mammary ducts with full representation of human DCIS histologic patterns. Tumor cells were incorporated into the normal mammary epithelium, developed ductal intraepithelial neoplasia and DCIS, and progressed to invasive carcinoma, suggesting the model provides a rigorous approach to study early stages of breast cancer progression. Mammary glands were evaluated for myoepithelium integrity with immunohistochemical assays. Progressive loss of the myoepithelial cell differentiation markers p63, calponin, and α-smooth muscle actin was observed in the mouse myoepithelium surrounding DCIS-involved ducts. p63 loss was an early indicator, calponin loss intermediate, and α-smooth muscle actin a later indicator of compromised myoepithelium. Loss of myoepithelial calponin was specifically associated with gain of the basal marker p63 in adjacent tumor cells. In single time point biopsies obtained from 16 women diagnosed with pure DCIS, a similar loss in myoepithelial cell markers was observed. These results suggest that further research is warranted into the role of myoepithelial cell p63 and calponin expression on DCIS progression to invasive disease.

Breast carcinoma metastasis to the lacrimal gland: Two case reports

A 77-year-old female, with proptosis, reduced eye motility and diplopia which had developed over two to three months and a 69-year-old female with proptosis, oedema of the eyelid, reduced motility and ptosis, which had developed over three weeks, are presented in the present study. Computed tomography scans revealed irregular lacrimal gland tumours in the two patients. The two patients had history of breast cancer. The first breast cancer metastasis in the lacrimal gland demonstrated a cribriform growth pattern containing ductal elements. The epithelial tumour cells stained positive for cytokeratin (1-8, 10, 14-16, 18 and 19), oestrogen receptor, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA) and gross cystic disease fluid protein 15 (GCDFP-15). The second metastatic tumour was positive for EMA and estrogen receptor, but variably positive for CEA and GCDFP-15. The metastasis in the lacrimal gland was a pleomorphic tumour. The tumour cells were positive for EMA and variably positive for oestrogen and CEA. Metastases to the lacrimal gland are extremely rare, and metastases to the lacrimal gland should be considered in the diagnoses of lacrimal gland tumours. The present study aimed to describe two such cases and draw attention to breast carcinomas as a differential diagnosis and the most frequent cause of lacrimal gland metastasis.

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.

Integration of molecular profiling and chemical imaging to elucidate fibroblast-microenvironment impact on cancer cell phenotype and endocrine resistance in breast cancer

The tumor microenvironment is known to play a key role in altering the properties and behavior of nearby cancer cells. Its influence on resistance to endocrine therapy and cancer relapse, however, is poorly understood. Here we investigate the interaction of mammary fibroblasts and estrogen receptor-positive breast cancer cells in three-dimensional culture models in order to characterize gene expression, cellular changes, and the secreted protein factors involved in the cellular cross-talk. We show that fibroblasts, which are the predominant cell type found in the stroma adjacent to the cancer cells in a tumor, induce an epithelial-to-mesenchymal transition in the cancer cells, leading to hormone-independent growth, a more invasive phenotype, and resistance to endocrine therapy. Here, we applied a label-free chemical imaging modality, Fourier transform infrared (FT-IR) spectroscopic imaging, to identify cells that had transitioned to hormone-independent growth. Both the molecular and chemical profiles identified here were translated from cell culture to patient samples: a secreted protein signature was used to stratify patient populations based on gene expression and FT-IR was used to characterize breast tumor patient biopsies. Our findings underscore the role of mammary fibroblasts in promoting aggressiveness and endocrine therapy resistance in ER-positive breast cancers and highlight the utility of FT-IR for the further characterization of breast cancer samples.

Theranostic and molecular classification of breast cancer

CONTEXT

Despite advances in breast cancer management, women continue to relapse and die of breast cancer. Traditionally, evaluation for hormone receptors (estrogen and progesterone), as well as HER2 overexpression, have guided therapy-related decision-making because they are both prognostic and predictive indicators. However, there are limitations with those studies, which can lead to improper treatment. Gene signatures have recently been shown to be of value in identifying molecular portraits of breast carcinoma and are beginning to play role in management and treatment algorithms.

OBJECTIVE

To provide a summary of the prognostic and predictive indicators of breast cancer, such as hormone receptors, HER2, and molecular gene signatures that currently help guide clinical decision making.

DATA SOURCES

Published articles from peer-reviewed journals in PubMed (US National Library of Medicine).

CONCLUSIONS

Emerging evidence shows promise that, in addition to hormone receptors and HER2 studies, evaluating tumors with gene expression profiling can provide additional prognostic and predictive information, further aiding clinical management and leading to a more personalized approach to treating breast cancer.

Can immunohistochemistry serve as an alternative to subjective histopathological diagnosis of oral epithelial dysplasia?

Many attempts have been made to identify objective molecular biomarkers to diagnose and prognosticate oral epithelial dysplasia (OED) because histopathological interpretation is subjective and lacks sensitivity. The majority of these efforts describe changes in gene expression at protein level in OED as determined by immunohistochemistry (IHC). However, the literature on these putative markers of oral cancer progression is vast and varied. The main purpose of this article is to review current knowledge on biomarkers of protein expression for OED by IHC approaches. We further discuss these findings in terms of the proposed essential hallmarks of cancer cells to better understand their role in oral oncogenesis.

Course introduction and selection of immunohistochemical staining panels: principles and importance of incorporating clinical information. The 5th annual retreat for applied immunohistochemistry and molecular pathology january 30th-february 2, 2011, coral gables, Florida

Among the core principles in the practice of immunohistochemistry is the use of carefully chosen marker panels. Choosing an appropriate panel of antibodies is predicated on a sound differential diagnosis that is based on detailed examination of hematoxylin and eosin-stained slides. The panel should contain antibodies designed to be immunoreactive in the most likely disease(s) in the differential as well as selected negative markers. In addition, the importance of detailed historical and clinical information in constructing the differential diagnosis and panel selection cannot be understated. Two cases from the Case Presentation sessions of the 5th Annual Retreat for Applied Immunohistochemistry and Molecular Pathology are summarized to illustrate these points. The first case is that of metastatic well-differentiated neuroendocrine tumor (carcinoid) tumor presenting as a breast mass. The second is that of a squamous cell carcinoma of the lung mimicking a tumor with admixed glandular differentiation by entrapment and disruption of bronchial glands. Application of a select immunohistochemistry panel in light of the differential diagnosis and importance of making a specific diagnosis are discussed.

Encapsulated apocrine papillary carcinoma of the breast--a tumour of uncertain malignant potential: report of five cases

Five cases of an unusual encapsulated apocrine papillary tumour are reported. All presented as cystic masses in the breast of women aged 44-84 years. Imaging studies showed a complex cyst often with one or more mural nodules. The key histological features are similar to those of classical encapsulated papillary carcinoma in that myoepithelial cells were absent within the papillary structures and at the periphery of the cyst. All were pure apocrine in type and showed variable degrees of cytological atypia and mitotic activity. All lacked evidence of malignancy in the breast tissue outside of the lesion. Sentinel lymph node biopsies performed in three of the cases were negative for metastases, and all have behaved in a benign fashion.

WT1 immunoreactivity in breast carcinoma: selective expression in pure and mixed mucinous subtypes

Current literature suggests that strong WT1 expression in a carcinoma of unknown origin virtually excludes a breast primary. Our previous pilot study on WT1 expression in breast carcinomas has shown WT1 expression in approximately 10% of carcinomas that show mixed micropapillary and mucinous morphology (Mod Pathol 2007;20(Suppl 2):38A). To definitively assess as to what subtype of breast carcinoma might express WT1 protein, we examined 153 cases of invasive breast carcinomas. These consisted of 63 consecutive carcinomas (contained 1 mucinous tumor), 20 cases with micropapillary morphology (12 pure and 8 mixed), 6 micropapillary 'mimics' (ductal no special type carcinomas with retraction artifacts), 33 pure mucinous carcinomas and 31 mixed mucinous carcinomas (mucinous mixed with other morphologic types). Overall, WT1 expression was identified in 33 carcinomas, that is, 22 of 34 (65%) pure mucinous carcinomas and in 11 of 33 (33%) mixed mucinous carcinomas. The non-mucinous component in these 11 mixed mucinous carcinomas was either a ductal no special type carcinoma (8 cases) or a micropapillary component (3 cases). WT1 expression level was similar in both the mucinous and the non-mucinous components. The degree of WT1 expression was generally weak to moderate (>90% cases) and rarely strong (<10% cases). None of the breast carcinoma subtype unassociated with mucinous component showed WT1 expression.