<prompt> The differential diagnosis of lesion, histologically resembling giant cell tumour in the small bones of the hands or feet, includes all of the following except:Aneursymal bone cystFibrosarcomaOsteosarcomaHyperparathyroidism  <response>: Ans. is b i.e. Fibrosarcoma Histological differential diagnosis of Giant cell tumorGiant cell reparative granuloma a benign reactive conditionBrown tumor of hyperparathyroidism Non-ossifying fibroma Benign fibrous histiocytoma Aneurysmal bone cyst Osteosarcoma with prominent giant cells.Metastatic ca with giant cells. 