Novel Clonal der(9)t(5;9)(q31;q34) Cytogenetic Translocation in a Giant Cell Tumor of Bone.

Giant cell tumor of the bone (GCTB) is a benign but locally aggressive neoplasm of long bones with higher chances of local recurrence. Many cytogenetic studies have reported clonal telomeric associations with GCTB. Here, we report for the first time a novel clonal translocation, der(9)t(5;9)(q31;q34), in a 25-year-old male patient with GCTB in the left distal femur. The biological significance of this translocation remains to be determined.