Bone scintigraphic and CT evaluation of chondrosarcoma of the rib: correlation with histological grade in 6 cases.

OBJECTIVE The objective of this study is to assess the value of CT and bone scintigraphic findings for grading of rib chondrosarcoma. METHODS Included in this study were six cases of histologically proven chondrosarcoma of the rib, in which bone scintigraphy and/or CT was performed. Correlation of histologic grade (I-III), tumor size on CT, CT grading (modified Brown's system), the pattern (nodular or peripheral, presence or absence of extended uptake pattern) and the intensity (Simon and Kirchner's grade, 0-4) of scintigraphic uptake were assessed. RESULTS CT grade was III, except for one case of dedifferentiated chondrosarcoma. Scintigraphic grade was 3 or 4 in all the cases. CONCLUSION The patterns of CT and bone scintigraphic findings more likely reflect the size of the mass and ossification, and are not well correlated with the histological grading.