Myoepithelial carcinoma of the breast with distant metastasis and accompanied by adenomyoepitheliomas

The Utility of SOX10 Immunohistochemical Staining in Breast Pathology

OBJECTIVES

SOX10 expression helps identify melanocytic lesions. Over time, novel uses have been identified, such as expression in triple-negative breast cancer (TNBC). We evaluated the usefulness of SOX10 in breast pathology-specifically, identification and subtyping of TNBC and distinction from gynecologic carcinomas, use as a myoepithelial marker, and in the distinction of usual ductal hyperplasia (UDH) from atypical ductal hyperplasia (ADH).

METHODS

Several breast and gynecologic carcinoma tissue microarrays containing a total of 492 cases were stained with SOX10. Whole sections of 34 ADH, 50 UDH, and 29 ductal carcinoma in situ (DCIS) samples were also stained with SOX10.

RESULTS

SOX10 expression was identified in 67% of consecutive TNBC cases. Expression was mostly seen in nonapocrine, androgen receptor (AR)-negative TNBCs. All gynecologic carcinomas (n = 157) were negative. All UDH cases showed mosaic SOX10 expression, while all ADH cases lacked expression. All estrogen receptor (ER)-positive DCIS (n = 19) specimens were negative for SOX10, while 2 of 10 ER-negative DCIS specimens were positive for SOX10. The latter 2 cases showed SOX10-positive invasive carcinomas.

CONCLUSIONS

SOX10 identifies nonluminal AR-type TNBC and is useful in distinguishing TNBC from gynecologic carcinomas. SOX10 can distinguish UDH from ADH. SOX10 is not useful in distinguishing ADH from DCIS.

Epithelial-myoepithelial carcinoma of the nasopharynx: A case report and review of the literature

Background

Epithelial-myoepithelial carcinoma (EMCa) is a rare low-grade malignant tumor that most commonly occurs in the salivary glands, with approximately 320 cases having been reported worldwide. Here, we report the third case of EMCa occurring in the nasopharynx. Rare cases in the breast, pituitary gland, lacrimal gland, nose, paranasal sinus, nasal cavity, trachea and bronchus, lung, and even the pleura mediastinalis have also been reported. Histopathology and immunohistochemistry are useful for confirming the diagnosis of EMCa, which is characterized by biphasic tubular structures composed of inner ductal and outer clear myoepithelial cells and stains for different markers in each layer. However, because of the rarity of EMCa, the clinicopathological characteristics and treatment of these patients remain unclear.

Case presentation

We report a rare case of EMCa of the nasopharynx. A 51-year-old man presented with a 5-month history of pain while swallowing and aggravation accompanied by right ear tinnitus lasting for 1 month. Nasopharyngoscopy and magnetic resonance imaging (MRI) of the nasopharynx and neck revealed a 5.6 cm × 3.4 cm × 3.1 cm mass in the nasopharyngeal space, invasion of the right cavernous sinus, and lymph node enlargement in the right retropharyngeal space. On 17 April 2019, based on the histopathological and immunohistochemical features, a final diagnosis of EMCa of the right nasopharynx was made. The patient underwent concurrent chemoradiotherapy (CCRT), and his symptoms were relieved after treatment. On 10 January 2022, nasopharynx MRI and biopsy revealed local recurrence, but chest and abdominal computed tomography (CT) showed no obvious signs of metastasis. The local recurrence-free survival (LRFS) period was 33 months.

Conclusion

To the best of our knowledge, this is the third reported case of EMCa in the nasopharynx and the only case of EMCa in the nasopharynx treated with CCRT, and a partial response was achieved. Therefore, to improve the quality of life and prognosis of patients with unresectable tumors, we believe that CCRT is a suitable option. Further clinical observations are required to elucidate the pathophysiology and prognosis of EMCa.

Adenomyoepithelioma of the breast: a rare diagnosis complicated by surgical emergency and diagnostic uncertainty

A woman in her 80s was referred as an emergency case with a large oedematous and ulcerating lesion of the right breast. There was a 5-month history of increasing breast volume with new onset skin breakdown and discharge. Imaging revealed an extensive heterogeneous mass requiring drainage. No diagnosis was received from multiple biopsies and immediate surgical resection of the breast and axillary sampling was prioritised given the deteriorating patient condition. Postoperative histology identified a biphasic Adenomyoepithelioma of low malignant potential, a rare presentation compounding the complexity of management. The diagnostic uncertainty of this case highlighted the importance of MDT collaboration and the flexibility of current management pathways when dealing with cases requiring urgent surgical intervention. Axillary sampling in the context of unsuccessful preoperative biopsy represented a comprehensive means for assessing the need for further surgical or systemic management in the context of unconfirmed malignancy in a deteriorating patient.

Malignant adenomyoepithelioma of the breast: Two case reports and review of the literature

BACKGROUND

Malignant adenomyoepithelioma (AME) of the breast is a rare tumor in which malignancy can arise from either epithelial or myoepithelial components, or from both cell types. The incidence and prognosis of malignant AME of the breast are difficult to assess due to its rarity. Therefore, the optimal treatment for this disease is still controversial.

CASE SUMMARY

We present two middle-aged women (48 and 56 years old) with malignant AME of the breast. Core needle biopsy was performed before surgery. However, breast adenoma and malignant tumors were observed. The preoperative diagnosis of malignant AME of the breast is still challenging for pathologists and clinicians. Both patients underwent mastectomy and sentinel lymph node biopsy, both of which were negative, followed by adjuvant chemotherapy.

CONCLUSION

The follow-up duration of the two patients was two years and four months, respectively. No signs of relapse or metastasis have been observed thus far.

Adenomyoepithelioma With Myoepithelial Carcinoma of the Breast With Axillary Lymph Node Metastasis: Two Case Reports and Review of the Literature

Objectives

Adenomyoepithelioma (AME) of the breast exhibits characteristic proliferation of the epithelial and myoepithelial cells. Most AMEs are benign, but the 2 inherent cell types can become malignant. The present study reports 2 cases of AME with myoepithelial carcinoma of the breast, one with axillary lymph node metastasis.

Methods

A modified radical mastectomy was performed in a 67-year-old woman, because a sentinel lymph node biopsy revealed one metastatic lymph node composed of a myoepithelial carcinoma component. Despite receiving radiotherapy and chemotherapy, the patient died from lung and brain metastases 21 months later. In the second case, breast-conserving surgery with sentinel lymph node biopsy was performed in a 55-year-old woman. Following additional treatment with radiotherapy and chemotherapy, there were no signs of recurrence or metastasis.

Results

The tumors of the 2 patients were diagnosed as malignant, based on their high mitotic rate and severe nuclear atypia.

Conclusions

Based on previously reported cases with distant metastases, the prognosis of myoepithelial carcinoma is poor. Myoepithelial carcinoma should be followed up with careful screening and treated aggressively.

Adenomyoepithelioma of the Breast

Adenomyoepithelioma of the breast is an uncommon tumor characterized by the presence of both epithelial and myoepithelial cells; its first full description was published in 1970 by Hamperl.

A 45-year-old woman presented a left breast lump that had been palpable for 4 weeks. There was no family history of breast cancer. Neither axillary nor supraclavicular lymph nodes were palpable. Craniocaudal mammography showed a 1.6 cm, well-defined nodule with several punctate intranodular calcifications in the subareolar region of the left breast. Color Doppler sonogram showed an ovoid, well-defined, homogeneous hypoechoic subareolar nodule with prominent peripheral vessels in the 6 o'clock position of the left breast. Operation was arranged and intraoperative frozen section examination revealed proliferation of round, oval or tubular glandular elements with intervening islands and bands of polygonal myoepithelial cells. Adenomyoepithelioma of the breast was the impression. Wide excision with adequate removal of the tumor and preservation of the left breast contour was successfully achieved. The diagnosis of adenomyoepithelioma of the breast was confirmed by immunohistochemical studies.

Breast adenomyoepithelioma: a case report with malignant proliferation of epithelial and myoepithelial elements

Background

Breast adenomyoepithelioma is an unusual tumor characterized by a biphasic proliferation of epithelial and myoepithelial cells. Most breast adenomyoepitheliomas are considered to be benign or to have a low-grade malignant potential, characterized by propensity for local recurrence. Malignant changes arising in this lesion are extremely rare and may involve one or both cellular components.

Case report

We discuss a case of a 60 year-old woman who began to experience pain in her right breast in January 2009. Breast ultrasound and mammography were performed showing a rounded, hypoechoic solid lesion with ill-defined margins in the right inner-inferior quadrant, suspicious of malignancy. Quadrantectomy of the inner-inferior quadrant of the right breast with sampling of ipsilateral axillary lymph nodes was performed. The histological analysis confirmed the diagnosis of adenomyoepithelioma with focal malignant change of the epithelial component, associated with high-grade malignant myoepithelial change. The patient was treated with adjuvant radiotherapy and her right breast received a dose of Gy 50 with a boost of Gy 10 to the tumor bed. At present, the patient shows no sign of tumor recurrence.

Conclusion

Breast malignant adenomyoepithelioma is a rare tumor which should be considered in the differential diagnosis of other solid breast lesions. Only few cases have been reported in the literature. Diagnosis, optimal therapy and predicting the outcome are problematic issues due to the rarity of this disease which appears to have hematogenous rather than lymphatic spread and usually occurs in primary tumors ≥ 1.6 cm in size.

K5/K14-positive cells contribute to salivary gland-like breast tumors with myoepithelial differentiation

Salivary gland-like tumors of the breast show a great variety of architectural patterns and cellular differentiations such as glandular, myoepithelial, squamous, and even mesenchymal phenotypes. However, currently little is known about the evolution and cellular differentiation of these tumors. For that reason, we performed an in situ triple immunofluorescence lineage/differentiation tracing (isTILT) and qRT-PCR study of basal (K5/K14), glandular (K7/K8/18), and epidermal-specific squamous (K10) keratins, p63, and smooth muscle actin (SMA; myoepithelial marker) with the aim to construct and trace different cell lineages and define their cellular hierarchy in tumors with myoepithelial differentiation. isTILT analysis of a series of 28 breast, salivary, and lacrimal gland tumors, including pleomorphic adenomas (n=8), epithelial-myoepithelial tumors (n=9), and adenoid cystic carcinomas (n=11) revealed that all tumor types contained K5/K14-positive progenitor cells in varying frequencies from a few percent up to 15%. These K5/K14-positive tumor cells were found to differentiate to glandular- (K8/18-positive) and myoepithelial-lineage (SMA-positive)-specific cells and were also shown to generate various heterologeous cell differentiations such as squamous and mesenchymal progenies. p63 was co-expressed with K5/K14 in basal-like progenitor cells, myoepithelial, and squamous cells but not in glandular cells. Our results show that the corresponding counterpart tumors of breast and salivary/lacrimal glands have identical cellular compositions. Taken together, our isTILT and RNA-expression data indicate that look-alike tumors of the breast represent a special subgroup of basal-type tumors with benign or usually low malignant potential.

Myoepithelial carcinoma of the breast treated with surgery and chemotherapy

Myoepithelial carcinoma (malignant myoepithelioma) of the breast is a rare tumor, for which only a limited number of reports have been published. Most of the reports emphasized diagnosis and pathology but not biological behavior and treatment. We report a 61-year-old patient with breast myoepithelial carcinoma who developed locoregional and distant metastases and received many chemotherapy regimens. She presented with an elastic hard mass of the left breast. Breast conserving surgery was performed as part of both diagnosis and treatment. From the results of histological and immunohistochemical examinations, this case was considered to be a myoepithelial carcinoma. Fifteen months after the completion of adjuvant radiotherapy, distant metastasis of the left parasternal lymph node metastasis developed. She was treated by further excision and received a total of four regimens of chemotherapy including a combination of doxorubicin and cyclophosphamide. She received chemotherapy for 20 months after the diagnosis of metastasis.

Myoepithelial and epithelial-myoepithelial, mesenchymal and fibroepithelial breast lesions: updates from the WHO Classification of Tumours of the Breast 2012

In the 4th edition of the WHO Classification of Tumours of the Breast, myoepithelial lesions are retitled myoepithelial and epithelial-myoepithelial lesions in order to better reflect the dual participation of luminal and myoepithelial compartments in some key entities. Malignant myoepithelioma, described as a section within the chapter on myoepithelial lesions in the 3rd edition, is recognised in the 4th edition as part of metaplastic carcinoma. Adenomyoepithelioma with malignancy is categorised in terms of the cellular component undergoing malignant transformation. The list of antibodies that can be used for identifying myoepithelial cells is updated. Among mesenchymal lesions, new additions are nodular fasciitis and atypical vascular lesions, while the haemangiopericytoma is removed. The 3rd edition stated that pathological prediction of behaviour of phyllodes tumours is difficult in the individual case. In the 4th edition, some progress has been made in prioritisation and weighting of histological parameters that can potentially estimate probability of recurrence. The WHO Working Group advocates leaning towards a diagnosis of fibroadenoma in cases where there is histological uncertainty in distinction from a benign phyllodes tumour, or adopting the neutral term 'benign fibroepithelial neoplasm', as the clinical behaviour of fibroadenoma overlaps with that of benign phyllodes tumour. The 3rd edition terminology of 'periductal stromal sarcoma' is revised to 'periductal stromal tumour', akin to the widespread consensus to avoid the use of the term 'cystosarcoma' in the context of phyllodes tumours.

Combined Epithelial-Myoepithelial Lesions of the Breast

Epithelial-myoepithelial proliferations of the breast are a heterogeneous poorly defined group of lesions characterized morphologically by dual differentiation into ductal (luminal) and myoepithelial cells. They include neoplastic and non-neoplastic entities that have overlapping morphologic features that may give rise to diagnostic difficulty. Many of these entities are low grade or of uncertain malignant potential but the biology of some of these rare lesions remains to be elucidated. This article discusses the differential diagnosis of epithelial-myoepithelial lesions of the breast and highlights the morphologic features of some of these entities.

Malignant adenomyoepithelioma of the breast with lymph node metastasis: a detailed immunohistochemical study

Malignant adenomyoepithelioma of the breast is a rare tumour with around 30 cases reported in the literature. Metastases associated with these tumours are usually haematogenous. Axillary lymph node metastases are thought to be unusual, and it has been recently suggested that axillary node dissection is not indicated unless clinically palpable. We here present a case of a 63-year-old woman, who developed a malignant adenomyoepithelioma with axillary lymph node metastasis, that included epithelial and myoepithelial elements, in spite of the absence of clinically enlarged nodes. We suggest that histological examination of axillary sentinel node(s) or node sampling may be worthwhile in this condition.

Adenomyoepithelioma of the breast: a review stressing its propensity for malignant transformation

This review describes the classification, clinical presentation, pathological features and clinical behaviour of adenomyoepithelioma (AME) of the breast. It is based on an extensive review of the literature and study of a collection of cases built up over a 17-year period at the British Columbia Cancer Agency. The diversity of the morphology encountered in both benign and malignant AME is described. The behaviour of malignant AME seems to be related to the grade of the malignant component.

Malignant myoepithelioma of the breast

Malignant myoepithelioma of the breast is rare. A 50-year-old Japanese woman was admitted to our hospital because of a right breast tumor (11 × 10 × 5.5 cm). Core needle biopsy revealed malignant spindle cells. A mastectomy was performed. The tumor consisted of malignant spindle, round, pleomorphic and giant cells with many mitotic figures and necrotic areas. Tumor and osteoclast-like giant cells were scattered. Much lymphovascular permeation was seen. In a few areas, particularly on the tumor periphery, there were merges between the tumor cells and myoepithelial cells of the non-tumorous ducts, as if the tumor emanated from the duct myoepithelium. The tumor was invasive into the skin and pectoral muscle. Immunohistochemically, the tumor cells were diffusely positive for vimentin, CD10, α-smooth muscle antigen, and Ki-67 (labeling = 95%). The significant areas of the tumor were positive for S100 protein, p63, p53, CD68, caldesmon, desmin and TGFβ1. A few areas were positive for pancytokeratin (AE1/3), cytokeratin (CK) 5/6, and CK 34βE12. In contrast, the tumor cells were negative for pancytokeratins (WSS, CAM5.2), CK7, CK8, CK14, CK18, CK19, CK20, EMA, CEA, bcl-2, myoglobin, CD34, CD56, CD45, HMB45, GFAP, α-1-antitrypsin, synaptophysin, estrogen receptor, progesterone receptor, HER2/neu, MUC1, MUC2, MUC5AC and MUC6. The author diagnosed the tumor as malignant myoepithelioma, as myoepithelial markers (C10, p63, S100 protein, α-smooth muscle actin, caldesmon) were positive, and also because there was a transition between the tumor cells and myoepithelium of non-tumorous ducts. The grade of the tumor was high. The patient was treated with chemoradiation and was free of disease 5 months after the operation.

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.

Biomarkers for Basal-like Breast Cancer

Initially recognized through microarray-based gene expression profiling, basal-like breast cancer, for which we lack effective targeted therapies, is an aggressive form of carcinoma with a predilection for younger women. With some success, immunohistochemical studies have attempted to reproduce the expression profile classification of breast cancer through identification of subtype-specific biomarkers. This review aims to present an in depth summary and analysis of the current status of basal-like breast cancer biomarker research. While a number of biomarkers show promise for future clinical application, the next logical step is a comprehensive investigation of all biomarkers against a gene expression profile gold standard for breast cancer subtype assignment.

Adenomyoepithelial Adenosis of the Breast: Clinical, Radiological, and Pathological Findings for Differential Diagnosis

BACKGROUND: Myoepithelial cells are widely present in the breast, and their hyperplasia may result in a spectrum of disease ranging from myoepitheliosis to myoepithelial carcinoma. CASE REPORT: A 46-year-old woman presented with a palpable mass in her right breast. Mammography and ultrasonography showed a lesion in the upper quadrant of the right breast with spiculated borders and shape. Excisional biopsy showed adenomyoepithelial adenosis. CONCLUSIONS: Although considered benign, adenomyoepithelial lesions tend to recur due to inadequate excision. Therefore, possibility of recurrence and even metastasis should be considered during follow-up of patients with a diagnosis of adenomyoepithelial lesions.

Immunohistochemical Analysis of Metastatic Neoplasms of the Central Nervous System

Metastatic neoplasms to the central nervous system are often encountered in the practice of surgical neuropathology. It is not uncommon for patients with systemic malignancies to present to medical attention because of symptoms from a brain metastasis and for the tissue samples procured from these lesions to represent the first tissue available to study a malignancy from an unknown primary. In general surgical pathology, the evaluation of a metastatic neoplasm of unknown primary is a very complicated process, requiring knowledge of numerous different tumor types, reagents, and staining patterns. The past few years, however, have seen a remarkable refinement in the immunohistochemical tools at our disposal that now empower neuropathologists to take an active role in defining the relatively limited subset of neoplasms that commonly metastasize to the central nervous system. This information can direct imaging studies to find the primary tumor in a patient with an unknown primary, clarify the likely primary site of origin in patients who have small tumors in multiple sites without an obvious primary lesion, or establish lesions as late metastases of remote malignancies. Furthermore, specific treatments can begin and additional invasive procedures may be prevented if the neuropathologic evaluation of metastatic neoplasms provides information beyond the traditional diagnosis of "metastatic neoplasm." In this review, differential cytokeratins, adjuvant markers, and organ-specific antibodies are described and the immunohistochemical signatures of metastatic neoplasms that are commonly seen by neuropathologists are discussed.

“Benign,” Metastasizing Adenomyoepithelioma of the Breast: A Report of 2 Cases

Adenomyoepitheliomas of the breast are rare tumors composed of a proliferation of 2 cell populations. For the most part, they are considered to be benign, but they locally recur. Those neoplasms that metastasize are deemed to have come from a histologically malignant primary tumor. Herein, we describe 2 cases of metastases of histologically “benign” adenomyoepitheliomas of the breast to the lung. In both cases, the primary neoplasms and the metastases did not show histologic features of malignancy. These unique cases represent another example of neoplasms that can metastasize in the absence of histologic features that would suggest malignant behavior. Establishing the diagnosis, determining optimal therapy, and predicting outcome are problematic because of the rarity of this entity. Perhaps, classification of adenomyoepitheliomas should be changed to recognize those neoplasms with malignant behavior.

Clonal analysis in glioblastoma with epithelial differentiation

Epithelial differentiation in glioblastomas (GBM) may be associated with circumscribed growth and focal keratin expression resembling carcinoma metastasis. Therefore these rare lesions can pose a diagnostic problem suggesting coincidental occurrence of two separate neoplasms. However molecular analysis should succeed in establishing a common origin of seemingly unrelated tumor samples. Five GBMs exhibiting epithelial differentiation were microdissected and analyzed for mutations in the TP53 gene. SSCP analysis of exons 5-8 was followed by direct sequencing of aberrantly migrating fragments. TP53 mutations were identified in tumors from two of five patients. A G-->T transversion in codon 176 was detected in a tumor, initially diagnosed as metastases of unknown origin, however, a later autopsy revealed GBM. In this lesion, the mutation was observed in both, areas of astrocytic differentiation and areas of epithelial differentiation. One tumor diagnosed as GBM with epithelial differentiation carried C-->T transition in codon 211 in both, areas of astrocytic and epithelial differentiation. Thus, molecular analysis proved clonality in two GBMs with epithelial differentiation, thereby excluding a collision tumor. The present data support the concept of clonal origin of these morphologically heterogeneous lesions.

Myoepithelial carcinoma arising in an adenomyoepithelioma of the breast: Case report with immunohistochemical and mutational analysis

Adenomyoepithelioma (AME) of the breast is an uncommon tumor characterized by biphasic proliferation of both epithelial and myoepithelial cells. In rare instances, the epithelial, the myoepithelial or both components of an AME may become malignant. Described herein is the case of a 69-year-old woman who presented with myoepithelial carcinoma of the breast in an AME. Malignancy of myoepithelial component (MEC) was evidenced by the presence of cytological atypia, high mitotic rate, necrosis and local invasion. Immunohistochemical study demonstrated strong expression of P53 and phosphorylated extracellular signal-regulated kinase 1/2 in MEC. Laser capture microdissection technique and mutational analysis further revealed point mutation of the p53 gene (T-->G transversion at codon 270) in this population, but not in glandular epithelial cells or adjacent normal ductal epithelium. No mutations in exons 1 and 2 of the K-, H-, and N-ras genes were identified in any of the neoplastic component. To the authors' knowledge this is the first report of a mutation in the p53 gene in a malignant AME of the breast.

Case report: myoepithelial carcinoma of the breast: a case report with imaging and pathological findings

We present a case of myoepithelial carcinoma of the breast together with illustrations of the imaging and pathological appearances as well as discussion on the management of this condition.

Metastatic myoepithelioma of the breast

Myoepitheliomas are typically benign tumours arising from exocrine glands. There have only been five reports of malignant myoepitheliomas from breast origin previously published in the English literature. This report describes a patient with myoepithelioma arising in the breast which later metastasized despite the primary tumour having benign histological features. Impaired immune function due to end-stage renal failure and haemodialysis may have contributed to the malignant potential of her tumour. The literature regarding myoepithelial tumours is reviewed. All breast myoepitheliomas should be managed as potentially malignant tumours with appropriate surgical clearance and staging.

Clinical presentation and long-term outcome of pure myoepithelial carcinoma of the breast

INTRODUCTION

Pure myoepithelial carcinoma of the breast is a rare tumour of controversial histogenesis. Little is known about its natural history and long-term outcome following treatment.

METHODS

All patients with pure myoepithelial carcinoma treated at our institution between 1970 and 2001 were studied with respect to pathological features, outcome and prognosis.

RESULTS

Six patients were identified. The median age was 60 (40-66) years and median follow-up was 34.5 months (range 14-76) months. Four tumours were T1 and one was T2 (one tumour size unknown). There were two moderately differentiated and three well-differentiated tumours (grade could not be assessed in one patient). Oestrogen and progesterone receptor could be assessed in five patients and all were negative. Primary treatment was wide local excision with clear radial margins. Lymph node assessment was negative in all patients. One patient received adjuvant radiotherapy. Three patients developed local recurrence at 15, 38 and 50 months and two patients developed distant metastasis at 30 and 79 months. The local recurrences were treated by further excision but two patients developed distant metastasis at intervals of 15 and 26 months, respectively. Two patients have died of the disease and four remain well. The 2-year and 5-year survival was 88% (SE, 6) and 55% (SE, 16), respectively. Large tumour size is a prognostic indicator of poor outcome.

CONCLUSION

Pure myoepithelial carcinoma of the breast adopts an aggressive clinical course with an outcome comparable to poorly differentiated adenocarcinoma of the breast.

[Breast myoepithelioma. Diagnostic and therapeutic difficulties. A case report]

Breast myoepithelioma is rare. The case of a 61-year-old female is reported here. The tumor was clinically, radiologically and macroscopically demarcated. Diagnosis was based on histological and immunohistochemical studies. At the time of diagnosis the tumor consisted of myoepithelial cells with few cellular atypias and a low mitotic activity. Tumor cells expressed vimentin, actin, S100 protein and cytokeratin. No local or distant metastases were found. The patient had been treated initially with a large excision of tumor. Local recurrences detected one year after initial surgery and showed a similar morphology and immunoreactivity with higher mitotic activity. Mastectomy with axillary dissection was performed. Neither recurrences nor distant metastases detected two years later. Myoepithelial tumors which are generally considered as benign or low-grade lesions can give rise to a wide range of clinical evolution.

Malignant myoepithelioma with a squamous epithelial component in the mammary gland of a cynomolgus monkey

A solid mass arising from the mammary gland was found in a 7-year-old female cynomolgus monkey. Histologically, the mass consisted of 2 components: spindle-shaped or ovoid sarcomatous cells and squamous epithelial cells. Metastatic nodules noted in the lung, liver and the gallbladder had the same histological features as the mammary mass. Immunohistochemistry revealed that the sarcomatous cells were positive for alpha-smooth muscle actin (alpha-SMA), vimentin, calponin, S-100 protein, epithelial membranous antigen (EMA), cytokeratin (large spectrum) and cytokeratin 14 (CK 14) in the cytoplasm, and p53, erbB-2 and progesterone receptor in the nuclei, but negative for desmin and estrogen receptor. The squamous epithelial cells were positive for EMA, cytokeratin (large spectrum) and CK 14, but negative for the rest. Both sarcomatous and squamous epithelial components were negative for glial fibrillary acidic protein (GFAP). Based on histological and immunohistochemical features, the present case was diagnosed as a malignant myoepithelioma with a squamous epithelial component in the mammary gland with distant metastases.

Salivary-type neoplasms of the breast and lung

Salivary-type tumors occur in multiple sites in the human body, likely related to a basic structural homology between exocrine glands in these different anatomic areas. This paper reviews these salivary gland tumor types in breast tissue and lung. Salivary-type tumors of both breast and lung are relatively uncommon in comparison to their salivary gland counterparts. This may be attributable in part to lack of familiarity with these tumors in extra-salivary sites, and in part to histologic overlap with other primary and metastatic tumor types. Recognition of these entities is improving as the clinical and pathologic features are better delineated, and tumors are more accurately classified. Prediction of malignant behavior is not always possible in these unusual sites. In some instances, such as adenoid cystic carcinoma, behavior is known to differ considerably from that of analogous primary salivary gland tumors and in other instances there are simply too few reported cases to allow for adequate prognostication. In fact, more recent papers discuss the need to consider a spectrum encompassing benign and malignant lesions, in both breast and lung. Of course, some entities show clear-cut evidence of malignancy with documented potential for metastasis, others show bland features and well-reported benign behavior, and the less well-defined entities reside between these two extremes. The molecular pathology of salivary gland tumors has been reasonably well investigated in that location; however; there are few molecular studies devoted to salivary-type tumors of the breast and lung. This represents a potential area for future growth in further clarifying these tumors and their behavior.

Multifocal, nascent, and invasive myoepithelial carcinoma (malignant myoepithelioma) of the breast: an immunohistochemical and ultrastructural study

This report describes the light microscopic (LM), immunohistochemical (IHC), and electron microscopic (EM) features of a multifocal, nascent, and invasive myoepithelial carcinoma of the breast. By LM, the spindle cells disclosed fibrillar acidophilic cytoplasm, mild nuclear atypia, and a low mitotic index. Myoepithelial differentiation was established through IHC (single- and double-labeling techniques) and EM: periductal and infiltrating spindle cells coexpressed total muscle actin, alpha-smooth muscle actin, vimentin, cytokeratin 14, and pankeratin, and their EM features were characteristic of myoepithelial cells, i.e., perinuclear tonofilaments, subplasmalemmal bundles of microfilaments with dense bodies, intermediate junctions, poorly developed desmosomes, pinocytic vesicles, and fragmented external lamina. No invasive epithelial cells disclosed luminal differentiation (by LM, IHC, EM), identifying, thus, this neoplasm as a pure spindle cell myoepithelial carcinoma of the breast.

Fine-needle aspiration cytology of benign and malignant adenomyoepithelioma: report of two cases

Cytological features of a malignant spindle-cell variant and a benign tubular variant of adenomyoepithelioma were examined to improve diagnosis of this tumor. Fine-needle aspiration cytology, of both a malignant and a benign case, characterized cellular and cohesive cell clusters composed of epithelial and myoepithelial cells. The smears of the malignant case were rich in spindle-shaped myoepithelial cells, admixed with a few epithelial cells. In about a fourth of the clusters, atypical cells with enlarged hyperchromatic nuclei and prominent nucleoli comprised more than 20% of cells. The smears of the benign case were composed of tubular epithelial cells surrounding one to several layers of myoepithelial cells with clear cytoplasm. Mild atypia was occasionally noticed. A review of the literature showed that a cytological diagnosis of malignancy is not warranted, if nuclear atypia is not generally severe. Focal severe atypia is not definitively indicative of benignity or malignancy.

Rare case of biphasic tumor of the breast with prominent CD34-positive spindle cells

We report an unusual case of biphasic tumor of the breast with prominent CD34-positive spindle cells. A 53-year-old woman presented with a mass in her right breast. Following an incisional biopsy, a partial mastectomy was done. Histologically, the tumor was a biphasic variant of a malignant spindle cell tumor of the breast. The lack of a leaf-like structure, together with the apparent myoid features of the spindle-shaped tumor cells, made it difficult to distinguish from malignant phyllodes tumor and from myoepithelial carcinoma. Immunohistochemistry revealed the spindle-shaped tumor cells to be myofibroblastic, but not myoepithelial in nature, ultimately categorizing this tumor as a malignant phyllodes tumor with prominent myofibroblastic differentiation.

Malignant adenomyoepithelioma of the breast with malignant proliferation of epithelial and myoepithelial elements: a case report and review of the literature

Malignant adenomyoepithelioma of the breast is a rare lesion characterized by malignant proliferation of epithelial and myoepithelial cells that show characteristic histologic and immunohistochemical features. Eleven cases have been reported, 4 of which showed evidence of distant metastasis. The authors report a case of malignant adenomyoepithelioma in the axillary tail of a 71-year-old woman, one of the oldest patients described so far, and review the literature. Malignancy in the current case was evidenced by the presence of local invasion, high mitotic rate, and severe cytologic atypia. The tumor was associated with adenosis and lobular adenomyoepithelial hyperplasia. Malignant adenomyoepithelioma is a rare neoplasm, diagnosable by light microscopy and immunohistochemistry. To date, it has only been reported in women, who ranged in age from 26 to 76 years. Metastases have only been documented in tumors 2.0 cm in diameter or larger.

Spindle cell tumours of the breast: practical approach to diagnosis

Spindle cell tumours of the breast are uncommon and often present diagnostic challenges. The most important is the sarcomatoid/metaplastic carcinoma, which has monophasic and biphasic variants. Each of these groups presents special diagnostic difficulties. In the monophasic variant the mesenchymal component predominates and the epithelial element forms a minor component often detected only after immunohistochemical study. The spindle cell areas may be bland and therefore under-diagnosed as nodular fasciitis or fibromatosis. Alternatively they may be highly malignant with a pattern that is misinterpreted as primary sarcoma of the breast. In the biphasic variant, the difficulty is in distinguishing between sarcomatoid carcinoma, myoepithelial carcinoma or malignant phyllodes tumour. Other spindle cell lesions of the breast include the various myofibroblastic tumours, the spindle cell variant of adenomyoepithelioma, the varied primary breast sarcomas, metastatic tumours with spindle cell morphology and, finally, the very rare follicular dendritic cell tumour. A simple practical approach to the diagnosis of spindle cell lesions is presented to help the general surgical pathologist to compile a differential diagnosis and to arrive at the correct conclusion

Epithelial-myoepithelial carcinoma arising in the nasal cavity: a case report and review of literature

Epithelial-myoepithelial carcinoma is an uncommon, low-grade, malignant epithelial neoplasm composed of variable proportions of ductular cells and large, clear staining, myoepithelial cells arranged around the periphery of the ducts. About 120 cases have been reported in the world literature, most of which were located in salivary glands, except for a few cases occurring in unusual locations such as breast, lacrimal gland, nose, paranasal sinus, trachea, bronchus, and lung. We here reported the second case of epithelial-myoepithelial carcinoma of the nasal cavity with extension to the nasopharynx. The patient was a 61 year old Chinese female with two month's history of progressive nasal obstruction. Histopathologically, the tumor showed typical myoepithelial and ductal cells biphasic differentiation, duct-like structure and infiltrating growth pattern. Some ductal cells showed the characteristics of oxyphilic cell, which had never been reported before. Recurrence and metastasis rates of epithelial-myoepithelial carcinoma varied from 35% to 50% and 8.1% to 25% respectively in different reports. The present case had neither recurrence nor metastasis twenty months after operation. When epithelial-myoepithelial carcinoma is mainly composed of spindle myoepithelial cells, the differential diagnosis should include myoepithelioma, neurofibroma, leiomyoma and hemangiopericytoma.

Malignant Adenomyoepithelioma of the Breast:A Case with Distant Metastases

Adenomyoepithelioma is thought to be a low-grade malignancy, and cases showing malignant behavior are rare. A massive breast tumor with skin invasion in a 60-year-old woman was diagnosed as malignant adenomyoepithelioma. Despite the tumor size and skin invasion, noaxillary lymph node metastases were detected. Light microscopy showed proliferation of tubular structures composed of atypical epithelial and myoepithelial cells and occasional anaplastic cells with mitotic figures extending to the epidermis of the skin. Twenty-four months after the surgery the patient complained of dull pain in the right thigh, and was found to have bone, lung and mediastinal lymph node metastases. There was neither local recurrence nor axillary lymph node metastasis. Subsequent femur fracture was treated by osteotomy. Despite additional chemoradiotherapy, the patient died 43 months after the first operation. Our case and literature review indicated that this tumor tends to show hematogenous metastasis.

Malignant adenomyoepithelioma of the breast with mixed osteogenic, spindle cell, and carcinomatous differentiation

A 50-year-old woman had a malignant tumor of the left breast, which recurred twice, metastasized, and caused death after 39 months. Histologically, the original neoplasm and the first recurrence comprised an adenomyoepithelioma, in addition to a sarcoma composed of trabeculae of mature and immature bone, osteoid, and partly calcified, dense collagenous tissue. The trabeculae were lined by alpha-smooth muscle actin-positive mononuclear tumor cells, which also extended into the stroma. Similarly, scattered osteoclastlike, multinucleate giant cells were present in the stroma and in the region of the trabeculae. This same pattern of adenomyoepithelioma and osteosarcoma also was seen in the last recurrence, together with a proliferation of undifferentiated malignant spindle-shaped cells. The last biopsy also contained a separate small focus of invasive ductal carcinoma of usual type. It was concluded that this, apparently unique, tumor probably represented an adenomyoepithelioma in which a metaplastic sarcoma of osteogenic and undifferentiated types developed from the myoepithelial element, and in which a carcinoma developed from the epithelial component.

Renal cell carcinoma: diagnosis based on metastatic manifestations

Renal cell carcinomas are notorious for their tendency to metastasize early, often before the primary tumor has become apparent. Frequently, the initial complaint is referable to a distant metastatic lesion. Metastatic lesions have been found in almost every organ or tissue of the body. When a patient with a clinically asymptomatic renal cell carcinoma has signs and symptoms referable to a localized lesion, the final diagnosis depends on histologic and cytologic evaluation of a biopsy specimen. In this article, we describe a patient who had a pulsating transcalvarial occipital-suboccipital mass as the initial manifestation of an occult renal cell carcinoma. Initial manifestations by site of metastasis described in the literature are reviewed, and the differential diagnosis of primary clear cell tumor versus metastatic lesions from a renal cell carcinoma, according to their pathologic features, is discussed.

Clear cell mammary malignant myoepithelioma with abundant glycogens

Malignant myoepithelioma (myoepithelial carcinoma) of the breast is extremely rare. A case is reported of a 46 year old female with clear cell mammary malignant myoepithelioma that, on histological examination, was glycogen abundant clear cell carcinoma. Immunohistochemically, the clear cells showed myoepithelial differentiation--that is, they were a smooth muscle actin and S100 protein positive. This case shows that glycogen abundant clear cell carcinoma is a variant of malignant myoepithelioma of the breast.

Adenomyoepithelioma of the Breast: A Case Reprot and a Review of Literature

A 74-year-old woman complained of a small nodule in the outer lower quadrant of her left breast. On physical examination, a 0.9 x 0.8 cm, round-shaped and firmly elastic nodule was palpated. Excisional biopsy was performed. Histologically, the tumor was separated into, with a bicellular pattern, containing both numerous glandular structures and numerous spindle-shaped cells. Immunohistochemical staining for EMA and cytokeratin showed strongly positive immunoreactivity for epithelial cells. Staining for &aipha;-SMA showed strongly positive immunoreactivity for myoepithelial components. Staining for keratin and S-100 protein showed weakly positive immunoreactivity for myoepithelial cells. Microscopically, the tumor was diagnosed as adenomyoepithelioma of the breast. Immunohistochemical examination is needed to distinguish epithelial cell proliferation from myoepithelial cell proliferation. Immunohistochemical examination using antibodies against EMA, alpha-SMA, Keratin, cytokeratin and S-100 protein, is indispensable.