[Giant cell tumor of soft tissues. Report of two cases].

We report two cases of giant-cell tumour of soft tissue (TCG-TM). The first case occurred in a 26-year-old woman presenting with a subcutaneous tumour of the left leg. Pathological study revealed a tumour comparable to benign giant cell tumour of bone. The patient is well without recurrence 10 months after the diagnosis. The second case concerned a 49-year-old man with a huge mass of the thigh. Microscopically, the tumour was composed of sheets of mononuclear and multinucleated cells. Mononuclear cells presented severe atypia and a high mitotic activity. Eighteen months later, the patient died with diffuse pulmonary metastases. TCG-TMs are uncommon and represent a distinct entity whose clinical behaviour and histological features are similar to giant-cell tumour of bone. The malignant variant is debatable. The differential diagnosis includes other tumours rich in osteoclast-like cells.