1/2. 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 = mixed tumour (Clic here for more details about this article) |
2/2. Unusual subcutaneous mixed tumour exhibiting adipose, fibroblastic, and epithelial components.A subcutaneous mass in the left supraclavicular fossa of a 55-year-old woman proved on histological examination to be composed of islands of squamous cells embedded in bands of spindle cells and associated with mature adipose tissue. Electron microscopy showed that the spindle cells were fibroblastic in nature and not squamous cells showing spindle differentiation. There was also a minor lymphangiomatous component and sparse infiltrates of lymphoid cells. The lesion bore certain similarities to thymolipoma except that the presence of spindle cells and the site were atypical. While it may be speculated that the tumour was thymolipoma occurring in an ectopic cervical thymus the lesion is provisionally regarded as an unusual mixed tumour featuring mesenchymal and epithelial components.- - - - - - - - - - ranking = 5keywords = mixed tumour (Clic here for more details about this article) |