Skip Lesions in Chondrosarcoma: Is Whole Bone Imaging Necessary?

Area of Science:

• Orthopedic Oncology
• Musculoskeletal Radiology
• Surgical Pathology

Background:

• Skip lesions in bone sarcoma are uncommon and associated with poorer outcomes in osteosarcoma and Ewing sarcoma.
• Whole bone imaging is recommended for osteosarcoma and Ewing sarcoma but lacks evidence in chondrosarcoma.

Purpose of the Study:

• To evaluate the incidence and characteristics of skip lesions in long bone chondrosarcoma.
• To determine the utility of whole bone imaging in identifying skip lesions in chondrosarcoma.

Main Methods:

• Retrospective review of 129 patients with long bone chondrosarcoma (1995-2022).
• Analysis of imaging studies (MRI, CT, bone scan) and pathology reports to identify skip lesions, defined as histology-confirmed tumor foci separated by normal bone.
• Correlation of skip lesion presence with tumor grade, location, and treatment.

Main Results:

• Skip lesions were identified in 3.9% of patients (5/129).
• All skip lesions were within 2 cm of the primary tumor, of the same grade, and visible on advanced imaging of the primary site.
• No transarticular skip lesions were found, and skip lesions did not alter surgical treatment plans.

Conclusions:

• Skip lesions are rare in long bone chondrosarcoma and are typically small and close to the primary tumor.
• Advanced whole bone imaging may offer low utility for detecting skip lesions in chondrosarcoma.
• The clinical significance and impact on treatment for skip lesions in chondrosarcoma require further investigation.