Clear Cell Variant of Chondrosarcoma

Clear cell chondrosarcoma is a low-grade malignancy that behaves less aggressively than conventional chondrosarcoma. It accounts for about 2% of all cases of chondrosarcoma, is more commonly seen in men, and usually affects patients in their 20s to 40s.

It tends to affect the epiphyses of long tubular bones, most commonly the femur and humerus. In such cases, patients can present with joint pain and effusion and limited range of motion.

Radiographs typically reveal a predominantly lytic lesion with a narrow zone of transition sometimes with a sclerotic margin. The lesion may be expansile, have central calcifications and ossifications, and demonstrate endosteal scalloping. Periosteal reaction and soft tissue extension are rare. The imaging appearance can mimic chondroblastoma, especially when seen in younger patients: While clear cell chondrosarcoma has homogeneous intermediate signal intensity on T1-weighted images and heterogeneous high signal intensity on T2-weighted images, chondroblastoma usually has low signal intensity on T1- and T2-weighted images.

Also of interest: cartilage lesions by age and location.

References

Greenspan A, Jundt G, Remagen W. Cartilage (Chondrogenic) Lesions. In Differential Diagnosis of Orthopaedic Oncology, 2nd Edition. 2007 Lippincott Williams & Wilkins; pp 222-224.