1/7. Malignant myoepithelioma of the salivary glands: clinicopathological and immunohistochemical features.Malignant myoepitheliomas (myoepithelial carcinomas) are uncommon, and we know of only 29 reported cases. We present a new case together with its clinical, histological, and immunohistochemical features. The tumour was located in the inferior vestibular sulcus of a 64-year-old woman. She was treated by wide local resection. Malignant myoepitheliomas are distinguished from benign myoepithelial neoplasms by their infiltrating and destructive growth. The tumour cells may be spindle-shaped or more rounded (plasmacytoid cells) and contain cellular pleomorphism and mitotic activity. The clinical and biological behaviour of this tumour is not yet known and there is little information about treatment and prognosis.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
2/7. 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 = behaviour (Clic here for more details about this article) |
3/7. Myoepitheliomas of the skin and soft tissues. Report of 12 cases.We describe 12 cutaneous and soft tissue myoepitheliomas, most of them in elderly patients. Morphologically the cutaneous and soft tissue myoepitheliomas revealed the same spectrum as their salivary gland counterparts. They were composed of a mixture of spindle, epithelioid and clear myoepithelial cells. Immunohistochemically they were positive to keratins and S-100 protein and reacted inconsistently with antibodies to smooth muscle actin. Morphologically they lacked any folliculo-sebaceous or apocrine differentiation. We believe that they are related to the eccrine type of cutaneous mixed tumours. Most cases had a benign behaviour, but 1 tumour metastasized, and the patient died of the tumour. Myoepitheliomas of soft tissues should be distinguished from other neoplasms with epithelial differentiation and from ossifying fibromyxoid tumour of soft parts, parachordoma and extraskeletal myxoid chondrosarcoma.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
4/7. Myoepithelial carcinoma of parotid gland: a case report.Myoepithelial carcinoma or malignant myoepithelioma are considered extremely rare malignant salivary gland neoplasms. Their clinical behaviour by literature seems variable: most studies reported good prognosis for low-grade malignancy and vice versa. Nevertheless long term survival has been described in patients with high-grade tumours, while patients with low-grade have been reported to develop metastases. We report a case of myoepithelial carcinoma of the parotid gland arising in pleomorphic adenoma in a 52-year-old woman with favourable course in long term follow-up.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
5/7. Pure malignant myoepitheliomas of the breast: an immunohistochemical study.Myoepithelioma of breast are extremely rare. We report two cases of pure malignant myoepithelioma of the breast, utilising light microscopic and immunohistochemical methods for diagnosis. Both the cases presented as breast lump. hematoxylin and Eosin (H&E) stained microscopic sections revealed a predominantly spindle cell tumor. Immunohistochemical work up was done. Case number one expressed positivity for vimentin, Smooth Muscle Actin (SMA), S-100 and CD10. Case number two expressed positivity for vimentin, CD10 and p63. This led to the diagnoses of malignant myoepithelioma in both of them. documentation of such cases prospectively and from archival material, using immunohistochemistry, is of extreme importance to assess the prevalence, various phenotypic patterns, long-term biological behaviour and to establish management protocols for malignant myoepithelioma.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
6/7. adenomyoepithelioma of the breast with a distinctive type of apocrine adenosis.A newly recognized type of dimorphic carcinoma of breast, distinct from adenoid cystic carcinoma, is described. It is characterized by a predominantly solid, clear cell myoepithelial proliferation, with centrally situated glandular lumina lined by apocrine cells. All cases arose in association with a distinctive type of atypical apocrine adenosis which has to be distinguished from microglandular adenosis and from tubular carcinoma. The biological behaviour of the tumour remains to be ascertained on the basis of longer follow-up, but it appears to have only limited malignant potential.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
7/7. Fine needle aspiration (FNA) cytology of adenoid cystic carcinoma and adenomyoepithelioma of breast: two lesions rich in myoepithelial cells.Adenoid cystic carcinoma and adenomyoepithelioma are relatively rare, but well described, breast lesions. The FNA cytology features in two cases of mammary adenoid cystic carcinoma and two cases of adenomyoepithelioma are described. In both cases of adenoid cystic carcinoma, aspirates consisted of tightly cohesive clusters of cells arranged around spheres and interconnecting cylinders of acellular material. The two aspirates of adenomyoepithelioma were composed of large tightly cohesive clusters of cells associated with small amounts of stromal material. In all four aspirates a dual population of epithelial and myoepithelial cells could be identified within cellular aggregates, and numerous bare nuclei were present. histology revealed the characteristic features of adenoid cystic carcinoma and adenomyoepithelioma. Immunohistochemical staining of histological sections for S-100 protein and alpha-smooth muscle actin confirmed the presence of large numbers of myoepithelial cells within all four lesions, providing indirect evidence that bare nuclei in breast aspirates represent myoepithelial cells. The presence of a dual population of epithelial and myoepithelial cells and of numerous bare nuclei within a breast aspirate is generally indicative of a benign lesion. This is not always the case, as adenoid cystic carcinoma is a malignant tumour, and adenomyoepithelioma, while generally exhibiting benign behaviour, is capable of local recurrence and distant metastasis.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |