A 40 years female presented with epiphyseal tumour at lower end radius. Diagnosis

i.e. (Giant cell tumour): (216-J. Maheshwari 3rd)* Osteoclastoma (Ginat cell tumour) is located at the epiphysis (old therapy)* Osteosarcoma and chondromyxoid fibroma are metaphyseal tumours while Ewing's sarcoma is diphyseal* The cells of origin is uncertain, Microscopically, the tumour consists of undifferentiated spindle cells, profusely interspersed with multinucleate giant cells. These giant cells were mistaken as osteoclasts in the past, hence the name Osteoclaustoma* Giant cell tumour is a lesion of uncertain origin that appears in mature bone (Apley)FeaturesOsteogenic SarcomaEwings sarcomaGiant cell tumourChondro-sarcomaAge (years)15-255-1520 - 40 (i.e. after epiphyseal fusion)30-60Common sitesLower end of femur, upper end of tibiaFemur, tibia, flat bones, multicentricLower femur, upper tibia, Lower radiusFlat bones upper end of femurLocationMetaphysisDiaphysis/* Endothelial cellsEpiphysis** regionAny where in the boneClinical featuresPain++* swelling**Duration-wks-monthPain**,swelling*Duration-wks-mths, often fever*Epiphysis** regionPain+, swelling*Duration-monthPain+, swelling+++, Duration- mths-yearsX-ray picture* Sunray appearance*** Codman's triangle*** Tumour new bone*Onion-peel appearance**Expansile lesion,ccentric location **Soap bubble appearance**Mottled calcification within the tumour**Differential diagnosisEwing's tumourOsteosarcomaOsteomyelitis* No calcification within tumour * MIC-2 is a specific markers**Aneurysmal bone cystFibrous dysplasiaOsteosarcoma* Osteoclaustoma & Chondroblastoma - Epiphysis* Giant cell tumour of bone is now associated with over expression of osteoprotegerin ligand (OPGL) an important stimulator of osteoclast differentian, suggesting overactivity of osteoclast in the etiology of the neoplasm* The benign giant cell tumour can later convert to a malignant condition such as osteosarcoma or malignant fibrous histiocytomaSite of origin of Primary bone neoplasmEpiphysisMetaphysisDiaphysis* Chondroblastoma* Giant cell tumour* Osteosarcoma* Chondroma* Chondrosarcoma* Osteoid osteoma* Osteochondroma* Brodie's abscess (not a tumour)* Ewing's sarcoma* Lymphoma* Myeloma* Adamantinoma* Osteoid osteoma