Cartilaginous
neoplasms are often histologically and therapeutically challenging. Predicting
biologic behavior can be difficult. In this study, 120 nonneoplastic, benign, and malignant cartilaginous lesions from 103 patients were cytogenetically analyzed in a 6-year period after short-term culture. For selected cases, fluorescent in situ hybridization (FISH) techniques using chromosome-specific probes were performed on metaphase/interphase preparations and on
paraffin-embedded tissue sections. Clonal abnormalities of chromosomes 2, 3, 5, 7, 8, and 12 were most frequently observed. Involvement of chromosomes 5, 8, and 12 may be etiologically significant because of the gene localizations for the human
cartilage link protein,
Langer-Giedion syndrome (a rare syndrome characterized by
multiple exostoses), and
type II collagen (a major component of normal cartilage) respectively, to these three chromosomes. That chromosome 7 abnormalities were observed only in malignant
tumors is of diagnostic value. The identity of three marker chromosomes and the significance of
trisomy 7 (a finding of controversial meaning), were determined with FISH. That the presence of
chromosome aberrations and increasing histologic grade strongly correlated (p = 0.001) is of prognostic importance. Moreover, complex aberrations were observed nearly exclusively in high-grade
tumors (p = 0.001). The data show that nonrandom chromosome loci are aberrantly affected in cartilaginous lesions and that these abnormalities may be of significant histopathogenetic consequence. In addition, these
chromosome abnormalities appear to be diagnostically and prognostically valuable in classifying and grading chondromatous
neoplasms.