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Autor*: S. Valníček
Description:
Ewing´s sarcoma is a primitive high malignant tumor of bone and soft tissues, usually metastasing to bone marrow and lung with the main occurrence in children and young adults.
Together with neuroblastoma, rhabdomyosarcoma, other primitive neuro-ectodermal tumors (PNET) and retinoblastoma account for the majority of metastases in children. While in neuroblastoma tumor rosettes are frequently present, in Ewing sarcoma and PNET they are rare (approximately in 10%). In the otherstumors mentioned above, rosettes are not found. There is considerable clinical and histological overlap between this tumor and PNET. Ewing sarcoma cells are usually less differentiated. Both these tumors share the same translocation t(11;22) (q24 q12) and the fusion gene named EWS/FLI-1.
Monoclonal antibodies to the fusion gene protein product are anti CD 99.
Tumors may be composed of small uniform cells with minimal morphologic evidence of differentiation or they may be composed of larger, less uniform cells with varying degre of neuroectodermal differentiation. CD 99 expression is identified in nearly all cases. PAS reaction in the cells is positive and disappears after digestion by diastase.
Zařazení*:
Ewingův sarkom
Přílohy*:
Description: A group of Ewings sarcoma cells.
Centrally a cell with a large nucleus and visible nucleoli, others cells with inconspicious nucleoli .
All cells with grey-blue, irregular stained cytoplasm, indistinct intercellular borders.
Description: A group of Ewings sarcoma cells.
Some cells with large and light-coloured nuclei, nucleoli are visible, other cells with smallish, darkly coloured nuclei, without visible nucleoli.
Grey-blue cytoplasm with fine vacuoles, indistinct intercellular borders.
Description: A group of Ewings sarcoma cells, indistinct intercellular borders.
Large cellular nuclei with visible nucleoli, smaler cells without visible nucleoli. Light basophillic colored cytoplasm containing basophillic inclusions, not typical for thisdiagnosis. Vacuoles in the cytoplasm of some cells.
Description: A group of Ewings sarcoma cells.
Significant cell anisocytosis. Largecells are containig trabecular and granular chromatine and visible bluish nucleoli, smaler cells have dark-colored chromatine without visible nucleoli. Light grey-blue and irregularly colored cytoplasm, indistinct intercellular borders.
Rarely see cytoplasmic vacuoles.
At the bottom of the picture, large platelet agregates seen