摘要:

Forty-seven angiosarcomas have been studied by light and electron microscopy. Neoplastic endothelial cells do not consistently display specific ultrastructural features, but certain aspects of the fine structure of the cells and their arrangement can be useful to establish or confirm the diagnosis. Experience with the common endothelial cell markers as diagnostic aids is briefly reviewed.

ISSN:0191-3123    

DOI:10.3109/01913128909057439

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Since ultrastructural examination is often employed to assess controversial soft tissue tumors, it is important to be aware of the range of differentiation assumed by the tumor cells in hemangiopericytomas. For this purpose, 35 examples (10 localized to the central nervous system and 25 located peripherally) were examined ultrastructurally, and, of these, 20 cases were also studied immunohistochemically for the presence of intermediate filaments and muscle-specific actin. Based on cytologic characteristics evident by electron microscopy, tumor cell differentiation was classed as pericytic (32%), myoid (8%), nondescript (48%), fibroblastic (4%), and histiocytic (8%). Vimentin was the only intermediate filament expressed in the normal pericytes of human fetal and adult tissues and in the neoplastic pericytes of all of the hemangiopericytomas. Muscle-specific actin was present in normal pericytes, but only focally in two of the hemangiopericytomas. In various combinations basal lamina-like materials, cytoplasmic processes, cytoplasmic filaments, discrete basal lamina, and poorly formed intercellular junctions were the most frequently noted features of the tumor cells in hemangiopericytomas, whether central or peripheral, and they assist, along with the organizational relationship of tumor cells and capillaries, in distinguishing this lesion from other soft tissue sarcomas.

ISSN:0191-3123    

DOI:10.3109/01913128909057440

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0191-3123    

DOI:10.3109/01913128909057441

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Based on histological, immunohistochemical, and ultrastructural studies, it is now apparent that the modified myoepithelial cell component of pleomorphic adenomas has a considerable range of cytolo-gical features. We reasoned that myoepitheliomas could be tumors with a similar spectrum of neoplastic myoepithelium but lacking the ductal element displayed in pleomorphic adenomas. A review of available salivary gland tumors identified 40 examples based on this definition. Architecturally, these myoepitheliomas displayed either nonmyxoid (solid), myxoid (pleomorphic adenoma-like), reticular (canalicularlike), or mixed growth patterns, while cytologically the lesions were composed of spindle-type (32.5%), hyaline-type (7.5%), epithelial-type (45.0%), clear-type (2.5%), or mixed-type (12.5%) tumor cells. Electron microscopy was carried out on eight examples and detailed immunohistochemistry on two methanol-fixed cases. As a result of the current review of myoepitheliomas and the description of similar lesions in the literature, it is our contention that salivary gland myoepitheliomas are not as rare as has been purported.

ISSN:0191-3123    

DOI:10.3109/01913128909057442

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

The ultrastructural and immunocytochemical findings in a series of 32 rarely encountered childhood renal malignancies are reviewed. The discussion includes anaplastic Wilms' tumors, renal clear cell sarcomas, rhabdoid tumors, carcinomas, sarcomas, neuroendocrine tumors, and lymphomas. An attempt is made to assess the relative merits of these two techniques in the differential diagnosis of these often troublesome lesions.

ISSN:0191-3123    

DOI:10.3109/01913128909057443

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0191-3123    

DOI:10.3109/01913128909057444

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0191-3123    

DOI:10.3109/01913128909057445

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0191-3123    

DOI:10.3109/01913128909057446

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0191-3123    

DOI:10.3109/01913128909057447

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

A small cell round tumor involving the chest wall of a 19-year-old female had features that by light microscopy were considered consistent with Ewing's tumor. At the ultrastructural level the cells contained small quantities of glycogen and had irregular dendritic processes with rare dense core granules and microtubules. Immunostaining for neuron-specific enolase was positive. The neoplasm is similar to reported cases of peripheral neuroectodermal tumor involving the chest wall of young patients.

ISSN:0191-3123    

DOI:10.3109/01913128909057448

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor