Cytogenetic analysis of a scapular chondromyxoid fibroma.

Chondromyxoid fibroma (CMF) is a rare cartilaginous tumor of bone. It typically presents in the lower extremities of young males. Cytogenetic analysis of two chondromyxoid fibromas has been previously reported. We studied a scapular CMF from an 11-year-old female by cytogenetic and molecular cytogenetic methods and found an unbalanced reciprocal translocation between the short arm of chromosome 3 and the long arm of chromosome 6. In this translocation, several bands from chromosome 3 (3p12, 3p13, 3p14, 3p21) are lost and several bands on chromosome 6 (6q21, 6q22, 6q23) appear rearranged. Two known cartilage-related genes are located in the regions affected by this unbalanced rearrangement: the type X collagen gene (COL10A1) located at 6q21-q22 and the parathyroid hormone/parathyroid hormone-related peptide receptor gene (PTH/PTHrP) located at 3p21.1-p22. These genes function to control growth and maturation of endochondral bone, the site of origin of cartilaginous tumors.