Sarcomatous transformation in a conventional Giant cell tumour of femur.

ABSTRACT

Although giant cell tumour (GCT) is seen quite frequently, malignant giant cell tumour (MGCT) is a rare entity occurring in less than 1% of patients with GCT. It can develop as a primary (de novo) or a secondary form. Secondary malignant giant cell tumour occurs as a result of previous attempts at local control of a benign GCT i.e. post-surgical or post-irradiation. Malignant transformation has been very rarely reported in patients with GCT who have not received radiation treatment. We report a rare case of sarcomatous transformation in a benign giant cell tumour occurring six years after the primary surgery for GCT and without radiotherapy. This report of malignant spindle cell transformation of a conventional GCT of bone strengths the theory that there is a mesenchymal cell line in GCT which can spontaneously transform into sarcoma. The prognosis of such patients is poor because the malignancies are usually high grade sarcomas. Key Messages Although giant cell tumour (GCT) is seen quite frequently, malignant giant cell tumour (MGCT) is a rare entity occurring in less than 1% of patients with GCT. It can develop as a primary (de novo) or a secondary form. The prognosis of such patients is poor because the malignancies are usually high grade sarcomas.