Pathomorphology of the sarcomas

摘要

Sarcomas (sarcomata - sa) are neoplasms that have a mesenchymal origin or are differentiating in that direction. Their growth is chaotic and progressive: the cells divide constantly in time and tumor space. They can be caused by viruses, chemical compounds, physical factors or even autoimmune reactions. They result from a disruption in a balance between protooncogenes and suppressor genes. This can be an effect of the accumulation of mutation within those genes, often with the participation of viruses that can modify the cell's genetic information. The changes in genes are transmitted from one generation of cells to subsequent ones and are irreparable and progressive. Sarcomas are vimentin-positive, S-100-negative, LCA-negative and HMB-45-negative. They can show positive or negative reactions to keratin and EM. The frequency of sarcomas as compared to cancers is like 1 : 50 and so they constitute approximately 1% of malignant neoplasms in humans. In animals this ratio is reversed: sarcomas (except in the mammary gland and skin) are far more common than carcinomas.