Late development of malignant fibrous histiocytoma at the site of a giant cell tumour 38 years after initial surgery.

The authors report on a patient who developed a malignant fibrous histiocytoma at the site of a benign giant cell tumour, which had been treated by curet tage 38 years previously. This latency period is, to their knowledge, the longest yet reported. This female patient was initially treated for a benign giant cell tumour of the proximal tibia when she was 33 years old ; she underwent curettage and Kiel bone grafting. She had not received radiation therapy. Twenty eight years later, she underwent a second operation due to recurrence of a tumour. No specific histological diag nosis was possible : histology suggested a benign tumour, however compatible with a low-grade malig nant potential but not associated with giant cell tumour. The patient underwent a third operation, with extensive curettage and total knee arthroplasty 38 years after the initial surgery, because of progres sive knee pain. Postoperative histopathology study showed high-grade malignant fibrous histiocytoma. Finally, she underwent above-knee amputation because of uncontrollabloe progression of the tumour. The use of xenogenic bone graft, bone cement and associated bone necrosis potentially contributed to the development of a malignant tumour adjacent to the primary giant cell tumour.