Cytogenetic findings and biologic behavior of giant cell tumors of bone

Giant cell tumor of bone is a benign but often aggressive lesion with a distinct tendency toward local recurrence and, rarely, malignant transformation. Over a 3‐year period, 20 giant cell tumors from 14 different patients were cytogenetically characterized. Random chromosomal abnormalities were detected in 14 of the 20 specimens and clonal chromosomal abnormalities were detected in six. An unusual anomaly, telomeric fusion, was the most striking random chromosomal abnormality detected. A comparison of the presence or absence of cytogenetic aberrations and the clinical behavior of these neoplasms was studied as well as a comparison of the aberrations in the initial specimen with those in subsequent specimens. Chromosomal abnormalities were detected in all but one of the ten tumors shown to be locally aggressive, recurrent, or metastatic. (The abnormalities observed in five of these tumors were clonal.) There were no chromosomal abnormalities present in three of four tumors that behaved in an innocent fashion. These findings support the presence of chromosomal abnormalities in giant cell tumors (telomeric fusion in particular) and suggest that cytogenetic analysis may be useful in predicting the biologic behavior of these neoplasms.