THE IMPORTANCE OF CYTOGENETIC ANALYSIS IN THE DIAGNOSIS AND TREATMENT OF BONE AND SOFT-TISSUE SARCOMAS

Introduction: Chromosomal analysis is becoming increasingly useful in the diagnosis and management of bone and soft-tissue sarcomas. The identification of chromosomal aberrations such as translations, deletions, additions of a part or whole chromosome, and other markers are associated with specific tumor subtypes. Material and Methods: Between 1998 and 2000, 78 bone and soft-tissue tumors were analyzed. Cytogenetic analysis was carried on a short-term cultured tissues by G-banding FISH and SKY procedures, as needed. Histopathological diagnoses included osteosarcoma – 16, Ewing’s sarcoma – 13, synovial sarcoma – 4, rhabdomyosarcoma – 4 (alveolar – 3, embryonal – 1), liposarcoma – 3, extra-abdominal fibromatosis – 3, alveolar soft part sarcoma – 12, and other soft-tissue sarcoma – 12. Other diagnoses included 8 hematological malignancies and 13 benign tumors. Results: Eight of the 16 osteosarcomas studies demonstrated complex hyperploid karyotypes compatible with the diagnosis of high-grade osteosarcoma. In most Ewing’s sarcoma, including three cases with a typical t(11;22) translocation, other chromosomal abnormalities such as trisomies of chromosomes 5,6,8, and 14 were observed. Three of the four synovial sarcomas had the typical t(X;18)(p11.2;q11.2) translocation. One of the synovial sarcomas was initially diagnosed on a histopathological basis as Ewing’s sarcoma but the cytogenetic analysis showed a complex X;18 translocation and led to change in diagnosis and related treatment. Only one of the alveolar rhabdomyosarcomas demonstrated the typical t(2;13)(q35;q14) translocation, while hypertetraploid set with double minutes (dmin) was detected in the other two cases. By using SKY, chromosome 1 was determined as the origin of one of the dmins, suggesting that PAX7 amplification could be involved in the pathogenesis of this tumor. Conclusions: Cytogenetic analysis of bone and soft-tissue tumors are of important clinical value for accurate diagnosis of tumor type. It can also provide information suggesting the pathogenesis of these tumors.