[Comparative histopathologic analysis of osteogenic sarcomas before and after initial chemotherapy]

We performed comparative histopathologic analysis of sections from diagnostic biopsy and surgical material obtained after antineoplastic chemotherapy. The sections were taken from 20 osteogenic sarcomas found in children and adolescents aged from 3 to 17. Chemotherapy used between samplings was based mainly on Adriamycin, and in four cases Methotrexate. Most frequent changes in histologic structure of the tumours after chemotherapy included further development of necrosis, a reduction of the structural homogeneity of the tumours and enhancement of cellular polymorphism. In many tumours we found enhancement or development of abilities to form cartilaginous foci. We did not observe maturation of the neoplasm induced by chemotherapy in the form of the development of highly differentiated bony tissue. The above-mentioned changes could be defected 3 to 4 weeks after chemotherapy initiation.