Giant cell tumour of the tendon sheath is a benign tumour and surgical removal of the tumour in its entirety is usually successful. However, the tumour can erode adjacent tissues such as bones, joints, tendons, blood vessels and nerves, and satellite foci can develop around the main tumour entity, making complete removal relatively difficult.
In addition, this tumour has an active cellular growth and is more likely to recur than ordinary benign tumours, with recurrence rates reported in the literature varying between 5% and 50%. Malignancy can occur in giant cell tumours of the tendon sheath, but is relatively rare.