Table 1: Clinical and histopathological differences between chondroblastoma, giant cell tumor and clear cell chondrosarcoma [7,14-17].
| Chondroblastoma | Giant Cell Tumor of Bone | Clear Cell Chondrosarcoma | |
| Clinical Features | - Epiphyseal, but could extend to metaphysis - 2nd-3rd decade - Secondary aneurysmal bone cyst possible |
- Usually metaphyseal - Ages 20-40 - Peripheral eggshell calcification - Secondary aneurysmal bone cyst possible |
- Epiphyseal - Very similar to chondroblastoma - Secondary aneurysmal bone cyst possible |
| Histopathology | - S-100 positive (negative result does not exclude diagnosis) - Reticular "chicken wire" calcification - Linear nuclear grooves - Chondroid matrix; patchy, scattered osteoclastic giant cells |
- S-100 negative - Osteoclastic giant cells contain large number of nuclei - Diffuse distribution of stromal cells and giant cells - Nuclei of mononuclear cells identical to those of giant cells |
- S-100 positive - Faintly lobulated - Abundant clear & eosinophilic cytoplasm, sharp cell borders, larger nuclei - Fewer, scattered osteoclastic giant cells - Cells mixed with reactive bone |