1/91. 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 = neoplasm (Clic here for more details about this article) |
2/91. 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 = 1.1910635223517keywords = breast (Clic here for more details about this article) |
3/91. 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 = neoplasm (Clic here for more details about this article) |
4/91. cytogenetic analysis of a primary salivary gland myoepithelioma.myoepithelioma, a rare benign salivary gland neoplasm, is a tumor composed entirely of myoepithelial cells. Unlike pleomorphic adenoma, these tumors lack any ductal epithelial differentiation, and manifest a minor stromal element. Previous cytogenetic and molecular genetic studies have mainly investigated pleomorphic adenomas and reported recurring specific chromosomal alterations at 8q12 and 12q13-q15 regions. The cell origin of these alterations, however, remains speculative. We report the cytogenetic analysis of a parotid myoepithelioma and discuss the putative origin for the cells with cytogenetic alterations. Our analysis shows 12q12 involved in a translocation with a previously unreported partner (1q), and nonrandom del(9)(q22.1q22.3) and del(13)(q12q22). Our results indicate that the myoepithelial cell is the source of those cells with chromosomal alterations, and that myoepithelioma shares 12q alterations reported in a subset of pleomorphic adenomas.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
5/91. 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 = 7.1463811341104keywords = breast (Clic here for more details about this article) |
6/91. myoepithelioma arising from the buccal gland: histopathological and immunohistochemical studies.A rare case of myoepithelioma of the buccal gland in a 54-year-old Japanese woman is reported. As the swelling exhibited a normal mucosal color and was relatively well defined, showing no ulcers, a benign salivary gland tumor was suspected upon clinical inspection. Microscopically, the parenchyma of the present case mainly consisted of plasmacytoid cells with round nuclei and eosinophilic cytoplasm, and partial spindle cells with eccentric nuclei. The stroma was composed of fibro-hyalinized or myxoid connective tissue that separated from the parenchyma. Immunohistochemically, the cytoplasm of the plasmacytoid and spindle cells was moderately positive for vimentin and GFAP, whereas the buccal gland adjacent to the tumor was negative for these antibodies. S-100 protein reactivity is strong for both types tumor cells. Actin reactivity was negative for both types of tumor cells, notwithstanding the fact that myoepithelial cells of the buccal gland were positively stained. Anti-cytokeratin reactivity was weak for both types of tumor cells in portions of the plexiform and solid areas; nevertheless, the buccal glands were moderately positive. These results suggest that neoplasmic myoepithelial cells exhibit abnormal differentiation and modification. There have been only two published reports of myoepithelioma arising from the buccal gland in the literature to date.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
7/91. 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 = 2.1910635223517keywords = breast, neoplasm (Clic here for more details about this article) |
8/91. Pulmonary epithelial-myoepithelial tumor of unproven malignant potential: report of a case and review of the literature.Epithelial-myoepithelial tumors of the lung are rare neoplasms whose biological behavior and clinical course still remain to be defined. A case of epithelial-myoepithelial tumor of the lung arising from bronchial mucosa-submucosa and occurring as a polypoid lesion of the upper left bronchus in a 47-year-old man is reported. The tumor did not infiltrate the cartilaginous wall of the bronchus and showed a biphasic histological appearance with a double layering of epithelial and myoepithelial cells. Myoepithelial spindle cells with eosinophilic cytoplasm were also observed. Mitotic figures were very rare and necrosis absent. Immunohistochemical study for epithelial and muscular markers confirmed the presence of a double-cell component in the tumor, namely epithelial and myoepithelial. The patient is alive and well, with no evidence of recurrent or metastatic disease 6 months after surgery. On the basis of the present case and the six previously reported cases, we suggest using the noncommittal term pulmonary epithelial-myoepithelial tumor of unproven malignant potential (PEMTUMP) for this type of neoplasm. In addition, we first introduce p63 as a novel marker for highlighting the myoepithelial cells of the respiratory tract and speculate on the role of these cells in the development of this unusual tumor.- - - - - - - - - - ranking = 2keywords = neoplasm (Clic here for more details about this article) |
9/91. myoepithelioma presenting as a midline cystic tongue lesion: cytology, histology, ancillary studies, and differential diagnosis.Salivary gland myoepithelioma (ME) is a neoplasm derived from myoepithelial cells that lacks the ductal and broad mesenchymal differentiation seen in the vast majority of mixed tumors. This report describes the cytologic findings of a cystic ME presenting in the midline of the dorsal tongue, a site where no salivary glands are generally present. The tumor was well circumscribed and composed of sheets of monotonous epithelioid cells without ductal cells. The cells were positive for S-100 protein and ultrastructurally had features of myoepithelial cells. The fine needle aspiration (FNA) biopsy findings, differential diagnosis, histology, immunohistochemistry, and electron microscopic features of this interesting and uncommon neoplasm are presented. To the best of our knowledge, there have been no cytologic reports of ME of the tongue.- - - - - - - - - - ranking = 2keywords = neoplasm (Clic here for more details about this article) |
10/91. myoepithelioma metastatic to the orbit.PURPOSE: To report a case of myoepithelioma metastatic to the orbit in an 11-year-old boy. methods: Interventional case report. An 11-year-old white male with a history of resection of a left thigh mass 10 months previously presented with a painless, rapid swelling of the left upper eyelid. Computed tomography scan and incisional biopsy of the orbital mass were performed. RESULTS: Immunohistochemical stains of the tumor in the left orbit and the previously resected mass were consistent with myoepithelioma. As a result of widespread metastases, the patient died 4 months after initial presentation to the eye clinic. CONCLUSION: myoepithelioma should be included in the differential diagnosis of neoplasms that can metastasize to the orbit in the pediatric age group.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
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