<prompt> Commonest site of the simple bone cyst isUpper end of femurLower end of femurUpper end of humerusLower end of humerus  <response>: Upper end of humerus 180- Ableys 8th Simple bone cyst - commonest being the upper end of the humerus Spine is commonest site of the osseous haemangioma Commonest site of Giant cell tumour - Distal femur, proximal tibia, proximal humerus and distal radius Commonest site of osteogenic sarcoma - Lower end of the femur, upper end of the tibia and upper end of the humerus Commonest site of Ewings sarcoma - usually in a tubular bone and especially in the Tibia, Fibula or clavicle Ewing s tumour is the commonest malignant tumour of flat bone, which has multi-centric origin Aneurysmal bone cyst - Tibia, Humerus 