Chromosome study of 249 patients examined for a bone tumor.

The authors have performed cytogenetic studies of bone tumors since 1987, and this article, based on previous work, summarizes their experiences in this field. Altogether 304 samples from 249 consecutive patients examined for a possible bone tumor at the Helsinki University Central Hospital, between October 1987 and April 1992, have been analyzed. The series consisted of 86 nonneoplastic disorders, 108 benign and 78 malignant primary bone tumors, and 32 other bone malignancies. In the group of nonneoplastic disorders, one sample from an infectious lesion demonstrated a simple clonal chromosome aberration. Simple clonal aberrations were seen in six of 75 successfully cultured benign tumors. Complex clonal aberrations occurred in 21 of 54 successfully cultured malignant primary bone tumors and in eight of 21 secondary bone malignancies. The complexity of clonal aberrations correlated with the grade of malignancy as the osteosarcomas and chondrosarcomas of high grade demonstrated chaotic abnormalities. The chaotic nature of the aberrations implicates the evolution of several different clones and thus advanced malignant transformation. Six of eight successfully cultured Ewing's sarcomas demonstrated the diagnostic t(11;22)(q24;q12); this translocation was also seen in one primitive neuroectodermal tumor. Cytogenetic study provides increasing knowledge of the biology of bone tumors and is a valuable adjunct in their evaluation.