Translocation of the HMGI-C (HMGA2) gene in a benign mesenchymoma (chondrolipoangioma)

Abstract.

Mesenchymomas are neoplasms in which there are at least two types of differentiated cells of mesenchymal derivation other than fibrous tissue. Chondrolipoangioma is a rare type of mesenchymoma composed predominantly of cartilage and adipose tissue with vascular elements and myxoid tissue present in lesser proportions. Cytogenetic analysis was performed on a case of chondrolipoangioma and revealed a t(12;15) (q13;q26) as the sole chromosome abnormality in 40 metaphases analyzed. However, using fluorescence in situ hybridization (FISH) analysis, a complex rearrangement was found involving chromosomes 2, 12, and 15, with a cryptic rearrangement of the gene (HMGI-C; HMGA2) coding for high-mobility group I protein. This finding suggests a role for the HMGI-C gene also in the pathogenesis of this uncommon benign tumor type, in addition to its well-established role in the pathogenesis of common benign tumors such as lipomas, uterine leiomyomas, pulmonary chondroid hamartomas, and endometrial polyps.