Sobre la heterogeneidad del sarcoma de Ewing óseo: caracterización ultrastructural de dos variantes morfológicas
1978; Volume: 13; Issue: 78 Linguagem: Espanhol
ISSN
2605-1656
Autores Tópico(s)Musculoskeletal synovial abnormalities and treatments
ResumoespanolEn el actual estudio se discuten 23 casos de sarcoma de Ewing con metodos opticos y microscopico electronicos. Basados en los criterios actuales creemos en la existencia de distintos tipos morfologicos de sarcoma de Ewing cuya histologia se extiende desde formas indiferenciadas blastemicas a otras mas atipicas e irregulares. La presencia de distintos tipos celulares blastemicos junto a otros mas electrodensos (celulas oscuras), sugiere que todas estas celulas se distingan solo en funcion de su grado de maduracion y diferenciacion metabolica. De esta forma se han podido distinguir dos tipos fundamentales de sarcoma de Ewing cuyas caracter:sticas fundamentales son las siguientes: Ewing tipico: Hemos reunido 15 casos de tal caracter estudiado con microscopia electronica. Este tumor esta formado casi exclusivamente por nidos solidos de celulas blastemales (celula matriz indiferenciada) en intimo contacto mutuo. Hay celulas blastemales provistas de glucogeno y otras desprovistas del mismo. El segundo tipo celular tiene caracter oscuro, denso, y su contenido en gluco- geno varla. Los capilares del tumor tienen densas basales y endotelio hiperplasico pero sin relacion directa con las celulas neoplasicas. Hay abundantes depositos de fibrina. Las fibras reticulares escasean o no existen. Hay frecuentes necrosis. Ewing atipico: En 8 casos hemos encontrado diverso grado de variacion en la morfologia y distribucion cuando se comparan con el anterior tipo de tumor. Aqui las celulas principales tienen una naturaleza mas irregular y se disponen con un caracter histiocitario o mesenquimal. El contenido en glucogeno es. mas escaso. Las celulas secundarias tambien aparecen. Ambos tipos celulares se asocian en grupos o mas aisladamente semejando al Ewing tipico. Los espacios intersticiales estan ocupados por vasos con densas basales y fibras reticulares mas abundantes. Alguna de estas celulas con tipologia mesenquinlal muestran filamentos compactos agrupados en qandas y asociados a mitocondrias. La diferenciacion celular histiocitica presenta un RER bien desarrollado asi como cisternas con actividad funcional. Hay lisosomas EnglishPresent report deals with 23 cases of Ewing's sarcoma analysed by optical and electronic microscopical means. On the basis of the present histological criteria we believe in the existence of several morphological types of Ewing's sarcoma whose histology extends from the most undifferentiated blastemal ones to a more atypical variante The presence of several cell types and the existence of transitional forms between the principal cell of a blastemal nature and the more in appearance electrodense ones (dark cell) suggest that all these cells seen in the same tumor differ only in their metabolic state of maturation. On this basis a relation could be established between the number of cells present in one given type of tumor and the ultrastructural nature of this neoplasm. On this basis two main types of Ewing's sarcoma have been identified whose characteristics are the following: Ewing typical: We have collected 15 cases of this nature in our ultrastructural analysed material. The tumors is almost exclusively composed of solid nests of blastemal cells (undifferentiated stem cells) which appear in very close contact with each other. Within similar cell structure there exislt two variants: wich glycogen and without glycogen. In very close relationship there are occasional dark cells (secondary cells) , with or without glycogen. In the interstitial spaces of the: tumor appear isolated capillaries provided with a dense basal and without any relationship to the neoplasic cells. There exist numerous deposits of fibrine. The reticular fibres are absent or in a very spars.e number. Necrosis is abundante Ewing atypical: In eight cases we have found some variations in cell distribution and morphology in relation to the first tumor group. Here, the principal cells have a more irregular nature being of a mesenchymal or histiocytic character and the glycogen content is sparse. Secondary cells are also present. Both kinds of cells appear isolated or located in groups or compact nests as typical Ewing do. In the interstitial spaces the vessels have: thick basals and the reticular fibres are more abundant. Some cells of mesenchymal nature are provided with filaments in cytoplasmic, bundles associated to mithocondria. The histocytic diflerentiated ones show a very well developed RER with cysternae in functional activity. There are lysosomes inside its cytoplasm.
Referência(s)