J Korean Bone Joint Tumor Soc.  2012 Jun;18(1):45-49. 10.5292/jkbjts.2012.18.1.45.

FDG-PET/CT Complements Bone Scan with Respect to the Detection of Skip Metastasis of Osteosarcoma: A Case Report

• Cheon GJ
• Choe JG
• Chae IJ
• Lee DH
• Song SH
• Kim MJ
• Park JH

• KMID: 1438413
• DOI: http://doi.org/10.5292/jkbjts.2012.18.1.45

Abstract

Skip lesion is not uncommon feature in osteosarcoma and considered to be importantly associated with poor prognosis factor, and thus, should be excised with the main mass. The accurate pre-operative evaluation of the intramedullary extent of osteosarcoma is essential, because it determines the level of bone resection. Among the reliable detection methods, bone scan has a drawback of high rate of false negative results and regional MRI has a difficulty to cover the whole involved lesions without clinical suspicion. The authors report a case of osteosarcoma of the distal femur with a proximal skip lesion that was not detected by either regional MR imaging or by bone scan, but which was visualized by FDG-PET/CT.

Keyword

skip metastasis; osteosarcoma; F-18 FDG-PET/CT; bone scintigraphy (BS)

MeSH Terms

Complement System Proteins
Femur
Neoplasm Metastasis
Osteosarcoma
Prognosis
Complement System Proteins

Figure

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  Figure 1 Plain radiographs show an osteolytic lesion of a medial aspect of distal femur in AP view.

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  Figure 2 Coronal and sagittal T1-weighted MR image at presentation show an osteosarcoma extending approximately 10 cm from the distal femoral articular surface. There is some soft tissue extension in medial direction.

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  Figure 3 Whole body bone scan at presentation showing isolated area of increased uptake in medial aspect of right distal femur. There is no suspected metastatic and skip lesion.

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  Figure 4 MR imaging of Right femur at the time of pre-operative restaging examination. T1 coronal and sagittal image of whole femur showing the skip lesion in proximal diaphysis.

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  Figure 5 Plain femur AP and Lat view showing no significant skip lesion of the proximal diaphysis.

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  Figure 6 Initial FDG-PET scan and restaging PET scan also showing distinct skip lesion.

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