1/46. Malignant myoepithelioma of the vulva resembling a rhabdoid tumour.AIMS: We report an example of malignant myoepithelioma of the vulva, which has not been hitherto described. We discuss the differential diagnosis and briefly review the literature. methods AND RESULTS: The lesion was found in an 81-year-old woman as an indolent 40 mm tumour. The neoplastic cells showed a myoid, spindled, epithelioid and plasmacytoid phenotype. Hyalinization of extracellular material and myxoid changes were present. There was a partly solid and microcystic pattern and a tight cohesiveness of cells was lacking. The circumscribed multinodular tumour somewhat resembled an extrarenal rhabdoid tumour, having large tumour cells with prominent nucleoli and large amounts of acidophilic cytoplasm. Immunohistochemically, the tumour cells were immunoreactive for cytokeratin, vimentin, muscle-specific actin, alpha-smooth muscle actin, and S100 protein, but not for desmin, epithelial membrane antigen, factor viii-related antigen, CD34 and CD31. CONCLUSIONS: The histological and cytomorphological appearance of the tumour well as the immunohistochemical findings suggest the diagnosis of malignant myoepithelioma, possibly derived from minor vestibulary glands or ectopic breast tissue. Differential diagnoses are, in particular, extrarenal rhabdoid tumour and 'proximal type' epithelioid sarcoma. Differentiation is important, because the tumours show a different behaviour and prognosis.- - - - - - - - - - ranking = 1keywords = breast (Clic here for more details about this article) |
2/46. Malignant myoepithelioma of the breast metastasizing to the jaw.A breast tumor in a 52-year-old female was interpreted as a malignant myoepithelioma based on morphological and immunohistochemical studies. The tumor consisted of elongated cells with clear cytoplasm and lacked glandular components. The tumor cells were stained positively for keratin, S-100 protein, glial fibrillary acidic protein (GFAP) and muscle-specific actin. Distant metastasis in the right jaw developed 8 years after the initial surgery and the metastatic deposit showed a similar morphology and immunoreactivity. Myoepithelial tumors are generally considered as benign or low-grade lesions and distant metastasis has been rarely documented. The present case presents the possibility of delayed occurrence of distant metastasis in myoepithelial tumor of the breast.- - - - - - - - - - ranking = 6keywords = breast (Clic here for more details about this article) |
3/46. Myoepithelial carcinoma of the lung arising from bronchial submucosa.Myoepithelial neoplasm mainly occurs in the salivary glands and breasts and is extremely rare in the lung. To our knowledge, this report describes the first documented case of a myoepithelial carcinoma present in the lung. The tumor derived from the right main bronchial submucosa and exhibited a dual epithelial and smooth muscular phenotype by immunohistochemical and ultrastructural studies. It invaded the neighboring pulmonary tissue and the hilar lymph nodes. Despite a right pneumonectomy and chemotherapy, metastasis was found in the left lung 7 months later.- - - - - - - - - - ranking = 1keywords = breast (Clic here for more details about this article) |
4/46. 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.- - - - - - - - - - ranking = 6keywords = breast (Clic here for more details about this article) |
5/46. Cutaneous myoepithelial neoplasms: clinicopathologic and immunohistochemical study of 20 cases suggesting a continuous spectrum ranging from benign mixed tumor of the skin to cutaneous myoepithelioma and myoepithelial carcinoma.BACKGROUND: Myoepithelial neoplasms, both benign and malignant, are rare but well-established clinicopathologic entities in the salivary glands, the breast, and the lung. Despite similarities between cutaneous sweat glands and glandular structures in the above-mentioned organs as well as the presence of regular myoepithelial cells around cutaneous eccrine/apocrine glands, the concept of cutaneous myoepithelial neoplasms is still debatable and not commonly accepted. methods: Twenty cutaneous myoepithelial neoplasms have been studied histologically and immunohistochemically. RESULTS: Nine neoplasms showed features of benign mixed tumor of the skin (chondroid syringoma) (five females and four males, age range 19-65 years, all cases arose in the head and neck region). Two cases represented the eccrine and seven the apocrine subtype. Interestingly, in three cases of the apocrine subtype, solid areas composed predominantly of myoepithelial cells were detected; these neoplasms were designated as benign mixed tumors with prominent myoepithelial cells. Nine cutaneous neoplasms were composed of spindled, epithelioid, and plasmocytoid cells without ductal differentiation and immunohistochemically stained variably positive for vimentin, epithelial and myogenic markers, S-100 protein, calponin, and glial fibrillary acidic protein (four females and five males, age range 3-71 years, four cases arose in the head and neck region and one case each on the finger, the thigh, the lower leg, the foot, and the breast, respectively); these neoplasms were designated as cutaneous myoepitheliomas. Two morphologically malignant neoplasms with cytologic and immunohistochemical features of myoepithelial cells arose on the face of a 70-year-old female and a 79-year-old male patient; these neoplasms were designated as malignant cutaneous myoepitheliomas (cutaneous myoepithelial carcinomas). CONCLUSIONS: The study suggests a continuous spectrum of cutaneous myoepithelial neoplasms ranging from benign mixed tumor of the skin to cutaneous myoepithelioma and cutaneous myoepithelial carcinoma. Further studies with extended follow-up information are necessary to establish prognostic factors.- - - - - - - - - - ranking = 2keywords = breast (Clic here for more details about this article) |
6/46. Clear cell myoepithelial carcinoma of the breast: a case report.Primary clear cell myoepithelial carcinoma (CCMC) is extremely rare. During the past twenty years, only one CCMC case has been reported. Here, a case of CCMC is reported. A 30-year-old woman became aware of an abnormal mass on the left breast, and quadrantectomy was performed. Microscopically, it consisted of tumor cells that had clear cytoplasm and showed an invasive growth pattern. Immunohistochemically, the tumor was positive for alpha-smooth muscle actin, S-100, partly positive for vimentin and epithelial membranous antigen. From these findings, the tumor was diagnosed as CCMC. Most of the clear cell myoepithelial tumors are probably misclassified in other examples. It is expected that the numbers of CCMC may be increased by routinely performing special stains and immunohistochemical stains, even without ultrastructual study.- - - - - - - - - - ranking = 5keywords = breast (Clic here for more details about this article) |
7/46. Intraductal growth of malignant mammary myoepithelioma.This report describes the histologic and immunohistologic features of an intraductal myoepithelial tumor that developed in the breast of a 61-year-old woman. Histologically, the tumor proliferated intraductally, with both a comedo or doughnut pattern and a solid pattern containing narrow fibrovascular cores, mimicking what appeared to be a conventional intraductal carcinoma. No fine papillary or arborizing growth or cribriform formation was observed. Tumor cells at the ductal peripheral zone were polygonal and clear with abundant glycogen in the cytoplasm; they were transformed into nonclear cells with slightly eosinophilic cytoplasm toward the center of the involved ducts. Occasionally, nonclear cells were elongated, with a centrally located cigar-shaped nucleus. These elongated or spindle cells tended to show a fascicular and streaming pattern similar to that of a smooth muscle tumor. Immunohistochemically, alpha smooth muscle actin (alpha-SM-actin) and S-100 protein were expressed in most of the nonclear cells. While clear cells also had a positive reaction for S-100 protein, they were mostly negative or barely positive for alpha-SM-actin. Epithelial membrane antigen (EMA) was also positive in a certain number of polygonal cells. These results support the myoepithelial nature of the present tumor, and some cells might also be immunologically differentiated into ductal epithelial cells. In addition to cytological atypia, frequent mitoses, and central necrosis within ducts, there was a minimal but evident stromal invasion, suggesting histological malignancy in this peculiar tumor.- - - - - - - - - - ranking = 1keywords = breast (Clic here for more details about this article) |
8/46. adenomyoepithelioma of the breast. A spectrum of biologic behavior.Adenomyoepitheliomas of the breast have been considered to have limited metastatic potential; axillary node metastasis has been reported, but there has been no report of distant metastasis. We report six cases, including two malignant adenomyoepitheliomas, one of which metastasized to the lung and brain. Patient age ranged from 26 to 63 years (mean 46). Primary tumors were solitary and measured 0.9-3.5 cm (mean 1.7). Five of six tumors presented as palpable masses. Two patients treated by local resection have no evidence of disease at 5 and 18 months' follow-up. Two patients treated by local resection had recurrences, one at 48 the other at 60 months. The fifth patient had a spindle-cell type adenomyoepithelioma diagnosed as malignant because of high mitotic rate and cytologic atypicality of the myoepithelial component. This patient was treated by mastectomy and has no evidence of disease at 18 months. The sixth patient, initially treated by local excision, had six local recurrences over 52 months treated by reexcisions, mastectomies, and radiation. A lung metastasis was resected at 54 months and brain metastases were identified at 60 months with death occurring at 64 months. Both malignant adenomyoepitheliomas had high mitotic rates [11-14/10 high-power fields (HPF)] diffusely throughout the tumors and foci of cytologically malignant cells. The malignant adenomyoepithelioma that metastasized had an infiltrative growth pattern that increased with successive local recurrences. The four other tumors had only isolated areas of mitotic activity (maximum 1-9/10 HPF) and minimal cytologic atypia. immunohistochemistry performed on five of six cases confirmed dual epithelial/myoepithelial cell populations in all tumors examined, including the metastasis. Electron microscopic examination of the malignant adenomyoepithelioma that metastasized also confirmed dual epithelial/myoepithelial cell populations in a local recurrence and the lung metastasis. We conclude that there is a spectrum of behavior for breast adenomyoepitheliomas with potential for local recurrence and, rarely, distant metastasis.- - - - - - - - - - ranking = 6keywords = breast (Clic here for more details about this article) |
9/46. Collagenous spherulosis in an adenomyoepithelioma of the breast.Collagenous spherulosis (CS) is an incidental finding that usually occurs in association with benign proliferative and preinvasive lesions. adenomyoepithelioma is a biphasic neoplasm of the breast, composed of both luminal epithelial and myoepithelial cells. Despite the common epimyoepithelial histogenesis, CS has never been described in association with adenomyoepithelioma. This report describes the case of a 48 year old woman who presented with CS of the breast in an adenomyoepithelioma. The combination of these two benign lesions led to diagnostic difficulties; namely, differentiation from adenoid cystic carcinoma, but also cribriform carcinoma and cylindroma of the breast. antibodies to the oestrogen receptor, progesterone receptor, p63, and c-kit (CD117) proved to be useful adjuncts to differentiate between these lesions.- - - - - - - - - - ranking = 7keywords = breast (Clic here for more details about this article) |
10/46. 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.- - - - - - - - - - ranking = 7keywords = breast (Clic here for more details about this article) |
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