Dedifferentiated chondrosarcoma with t(9;22)(q34;q11-12).

Translocation t(9;22)(q22-31;q11-12) is associated with the myxoid variant of chondrosarcoma. We present here a report of a patient with a dedifferentiated grade IV chondrosarcoma, which originated from the iliac bone and contained areas of grade I chondrosarcoma. There was no evidence of myxoid differentiation. The tumor had the karyotype 46,X,-X,t(9;22)(q34;q11-12), + mar[5]/52-61,x?,2-3 min,inc[9]/46,XX[2]. It is possible that the different breakpoints in the t(9;22) may reflect different histopathologic subgroups of chondrosarcoma.