Tumor progression in a giant cell type malignant fibrous histiocytoma of bone: clinical, radiologic, histologic, and cytogenetic evidence.

A malignant fibrous histiocytoma (MFH) of bone arising in the fibula of a 21-year-old woman is described. Clinical, radiologic, and histologic findings demonstrated rapid tumor progression. Chromosomal analysis of the biopsy specimen showed great karyotypic heterogeneity, whereas the resection specimen four weeks later displayed a rather homogeneous karyotype. Both revealed a clonal t(14;22)(q11;p12). Several other clonal and non-clonal chromosomal aberrations were observed. Some of these were previously described in giant cell tumor of bone (GCTB) and may correlate with aggressive behavior, e.g., aberrations involving 8p11, 19q13, and 20q13. The change from karyotypic heterogeneity to relative homogeneity may be related to tumor progression. The chromosomal findings further suggest that the giant cell type of MFH of bone may be related to malignant GCTB.