Giant cell tumour of talus with osteosarcomatous transformation in a young male: a case report.

A case of osteosarcomatous transformation in a benign giant cell tumour is described. Spontaneous malignant transformation is rare in a giant cell tumour with only 17 cases reported in the literature till date. In addition, a giant cell tumour arising in the bones of the hands and feet is in itself a rarity. In this instance the lesion presented in the talus of the left ankle in a 13 year old male.