Tissue culture, DNA flow cytometric and cytogenetic studies of a giant cell tumor of bone.

An in vitro tissue culture was established using a giant cell bone tumor derived from a 66-year-old female. The tumor was clinically classified as stage 2, and grade 1 histologically. Morphological observations including, in vitro growth character, histochemical and immunohistochemical staining, and ultrastructural studies, support that the giant cell originated from the mononucleated stromal cell. They do not belong to the monocyte-macrophage system. In this aggressive case, we also tried to evaluate the significance of using DNA ploidy flow cytometry, and chromosomal study in predicting its clinical outcome. The DNA ploidies of both the primary and cultured tumor cells were diploid. The chromosomal analyses revealed its chromosome number ranging from 43 to 46 with three clonal structural changes; dic (19;20) (p13;q13), dic (19;22) (q13;q13) and dic (12;?) (p13;?). As previously compared and reported, cases with marker chromosomes usually had a more aggressive clinical course than those without marker chromosomes. Instability of the terminal portion of the F- and G- chromosome groups were reported in other studies and were also detected in our case. Possible association of clinical aggressiveness with the clonal structural changes, especially dic (19;20) (p;q) and dic (19;22) (q;q), needed further investigation.