OrthoNet

Chondroblastoma

- benign tumors occurring in 2nd decade
- commonly found in proximal humerus, distal femur or proximal tibia (epiphysis of long bones but may be in an apophysis)

Signs & Symptoms:
- pain localized to region of tumor
- tenderness, pain on motion of the affected joint

Xrays:
- radiolucent lesion with well-defined sclerotic border with variable calcification in lesion
- may cross open physis & expand surrounding bone

Histology:
- round to polyhedral cells with well-defined cell borders containing indented nuclei
- matrix calcification may be present
- multinucleated giant cells - scattered & sometimes in large numbers
- cystic spaces resembling aneurismal bone cysts may be seen

Treatment:
- crettage & bone grafting à 90% cure rate
- rarely are locally aggressive or can metastasize