Cytogenetic and flow cytometric analysis of a clear cell chondrosarcoma

Cytogenetic analysis of a rare tumor, a clear cell chondrosarcoma of the spine, showed unusual karyotypic findings. The tumor had a predominant clone with a near-haploid chromosome complement of 30 chromosomes with loss of one homologue of each chromosome pair except chromosomes 5, 7, 12, and 19-22. A second clone with 58-60 chromosomes appeared to have originated by a doubling of the near-haploid clone. No structural changes were present. Comparison with other solid tumors and leukemias with near-haploid chromosome complements showed an interesting difference in the chromosomes which were preferentially disomic or monosomic in the two groups. Quantitative DNA analysis also showed aneuploid clones of cells corresponding to the near-haploid and hyperdiploid chromosome counts obtained cytogenetically.