Low grade central chondrosarcoma of the fifth costotransverse joint.

Chondrosarcoma (CHS) is the third most frequent primary malignant tumour of bone exceeded only by myeloma and osteosarcoma. It usually occurs in the trunk bones (pelvic girdle, shoulder, ribs) followed by the femur and humerus and is very rare in the spine accounting for about 5% of all CHSs. The majority of patients affected are over 50 years old. We report a case of a 22-year-old woman with a 2-month history of pain on the right side of the upper thoracic spine. Complete imaging work-up with radiographs, CT, MRI and digital subtraction angiography showed an osteolytic lesion of the right transverse process of T5 with extension into the ipsilateral rib and enhancing extracompartmental tissue involving the paraspinal muscles. Both CT-guided core needle biopsy and excisional biopsy were consistent with grade I central CHS with myxoid change and focal areas of Grade II CHS.