We report cytogenetic findings in short-term cell cultures from five enchondromas and four chondrosarcomas. Clonal chromosome aberrations were found in one case of enchondroma, and in all cases of chondrosarcoma. The only enchondroma with nonrandom abnormalities had a reciprocal t(8;17)(q23;p13), and monosomies 9, 19, and/or 22. In contrast to the few karyotypic findings in one of five enchondromas, the four chondrosarcomas were commonly characterized by cytogenetic heterogeneity, with a tendency for increasing karyotypic complexity in higher grade tumors. Two cases, one grade III and one metastasizing grade II chondrosarcoma, revealed hypodiploid stem- and sidelines with loss of chromosomes 6, 10, 13, 14, and 22, as common chromosomal abnormalities, suggesting a distinct karyotypic pattern in a subset of biologically aggressive chondrosarcomas.

We report a case of a solitary enchondroma located in the head of the left fibula in a 50-year-old patient and present the findings of histopathologic investigation and cytogenetic analysis. The tumor revealed simple karyotypic abnormalities with t(8;17)(q23;p13) and loss of chromosomes 9, 19, and 22 as clonal chromosomal changes. Only a few enchondromas with chromosome aberrations have been published previously; nevertheless, it appears that benign and malignant cartilaginous tumors may have similar chromosomal abnormalities.