CYTOGENETIC FINDINGS IN 33 OSTEOSARCOMAS

Thirty-three osteosarcomas (OS) were analyzed cytogenetically. Clonal chromosome changes were detected in 17 cases. Six tumors had chromosom e numbers in the diploid range, 6 in the triploid range, 1 in the tetr aploid range and 1 in the pentaploid range, while 3 tumors had multipl e clones with different ploidy levels. Including the present 17 tumors , a total of 27 OS with clonal aberrations have been reported. The rec ognizable structural rearrangements in these 27 tumors clustered to ch romosome arms 1p, 1q, 3p, 3q, 7q, 11p, 17p and 22q. Chromosome bands 1 q11, 1q21, 1q42 and 7q11 were the most frequently rearranged, and the most common numerical rearrangements were -3, -10, -13 and -15. Supern umerary ring chromosomes, in 2 tumors as the sole change, were found i n all 3 parosteal OS, which is in agreement with the findings in 1 pre viously reported parosteal OS. The association between ring formation and parosteal morphology represents the first cytogenetic-morphologic entity among OS. (C) 1993 Wiley-Liss, Inc.