1/5. Perivascular myoma: case report with immunohistochemical and ultrastructural studies.A subcutaneous myopericytoma-type perivascular myoma arising in the elbow of a 61-year-old woman is described. The tumor was well demarcated and consisted microscopically of small ovoid and spindle cells arranged in a concentric fashion, surrounding small to medium-sized vessels and imparting a superficial resemblance to hemangiopericytoma. In some areas, the cellular whorls were separated by myxoid stroma. cells located between cellular whorls appeared immature with scant cytoplasm but did not show distinct nuclear anaplasia, increased mitoses or foci of necrosis. immunohistochemistry showed that constituent cells were positive for alpha-smooth muscle actin and desmin. Electron microscopy disclosed that the immature-looking cells, as well as the ovoid and spindle-shaped cells, possessed focal densities along with thin filaments, subplasmalemmal densities, pinocytotic vesicles and an external lamina. These ultrastructural and immunohistochemical features indicate a myoid nature of pericytic cells and justify this type of neoplasm being categorized as perivascular myoid tumor.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/5. Intravascular myopericytoma.BACKGROUND: Myopericytoma is a benign tumor composed of cells that show apparent differentiation towards putative perivascular myoid cells called myopericytes. It arises most commonly in the dermis or subcutaneous tissue of the extremities in adults. methods: We describe a myopericytoma that was unusual in its intravascular location. RESULTS: A 54-year-old man presented with a 10-year history of a painful slowly growing 1.5-cm nodule in the subcutaneous tissue of the thigh. Histologic examination of the excised lesion showed that is was entirely contained within the lumen of a vein. It was composed of a proliferation of myoid-appearing spindle cells, which were arranged in a striking concentric pattern around numerous blood vessels, in a manner that accentuated the vessel walls. This pattern is characteristic of myopericytoma. In some areas, fascicles of spindle cells, embedded in a myxoid stroma, bulged into the lumina of lesional vessels, reminiscent of myofibroma/myofibromatosis. Lesional spindle cells were diffusely positive for smooth muscle actin, focally positive for CD34 and were negative for desmin, cytokeratin, S100 protein, HMB-45 and CD31. CONCLUSION: This case illustrates that myopericytoma can be entirely intravascular in its location.- - - - - - - - - - ranking = 3keywords = vessel (Clic here for more details about this article) |
3/5. Malignant myopericytoma: expanding the spectrum of tumours with myopericytic differentiation.AIMS: The spectrum of tumours showing myopericytic differentiation is increasingly being defined and includes lesions such as myofibroma and infantile haemangiopericytoma. Here we seek to describe for the first time and clinicopathologically characterize examples of malignant myopericytoma. methods AND RESULTS: Five cases of malignant myopericytoma were identified in the authors' consultation files. Immunostains were performed and clinical information was obtained. Tumours arose in three females and two males (median age 67 years, range 19-81 years) on the neck, arm, thigh and foot. One patient presented with disseminated metastases. One patient had a prior history of multiple benign myopericytomas in the same location. Four patients developed metastases and three died within 1 year. Tumours were composed of highly mitotic myoid-appearing ovoid-to-spindle cells showing at least focally striking perivascular orientation resembling that seen in benign myopericytoma; three cases were focally fascicular and three showed thin-walled branching vessels. All tumours showed at least focally prominent positivity for smooth muscle actin. One case showed dot-like desmin positivity. CONCLUSIONS: In reporting examples of malignant myopericytoma, we further characterize and broaden the morphological spectrum of myopericytic neoplasms. Available data indicate that malignant myopericytomas are associated with aggressive clinical behaviour.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
4/5. Perivascular myoma of myopericytoma and myofibromatosis-type arising in a chronic scar.We describe a case of a cutaneous perivascular myoma with features overlapping between the myofibromatosis and the myopericytoma type. The patient is a 58-year-old woman with a painless plaque-like and multinodular lesion in the pretibial dermis and subcutaneous tissue. She had repeated trauma to this site, first in her early youth that left an area of hyperpigmentation, and then again at age 40. The biopsy showed a biphasic pattern with a myofibromatosis-type component composed of spindle cell myoid nodules and more cellular round cell areas. The myopericytoma-like areas appeared to be infiltrating along vessels. These areas contained aggregates of immature-appearing cells arranged concentrically around vascular lumina in a manner reminiscent of pericytes. Immunohistochemical stains showed focal positivity for smooth muscle actin. Immunohistochemical and ultrastructural studies have showed these pericyte-like cells to be of a myoid origin. The reason for the neoplastic proliferation of perivascular myoid cells is presently unknown. The association of trauma and neoplastic transformation of the skin is rare. We report the first case of a cutaneous perivascular myoma arising in a chronic scar.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
5/5. Bronchogenic glomangiomyoma with local intravenous infiltration.Most glomus tumours occur in the dermis and subcutaneous tissues. lung glomus tumours are quite rare. The current authors present the first reported case of a lung-derived glomangiomyoma, the rarest variant of glomus tumour. A 56-yr-old female was admitted with haemoptysis. Chest computed tomography showed an approximately 5-cm-diameter mass in the right lower lobe with mucoid impaction. After a right lower lobectomy, a diagnosis of glomangiomyoma was made. The tumour had grown endobronchially and its maximal diameter was 5.5 cm. Although cytologically benign, glomus tumour cells had visibly infiltrated neighbouring vessels. These results suggest that a bronchogenic glomangiomyoma has a low-grade malignancy potential and warrants close follow-up.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |