Metastatic malignant chondroblastoma.

A case of malignant chondroblastoma with metastases is reported. The patient initially presented with a lytic lesion in his left pubic ramus. He was treated with curettage, but the lesion recurred 3 years later. After repeated curettage, radiation therapy, and the late development of multiple bone and soft-tissue metastases, he succumbed to his disease 13 years after diagnosis. The surgical pathology from each of his several procedures was reviewed. Although no definite malignant transformation was apparent, a metastatic deposit curetted 3 months prior to death showed some increase in mitotic activity. Flow cytometry of specimens from the patient's first local recurrence and a late distant metastasis was performed and revealed the interval development of a minor aneuploid peak between the two samples. This fatal chondroblastoma is the only one in our series of 80 patients treated over the past 25 years.