Giant cell tumors are painless swellings of the hand or fingers near tendon sheaths. Affected patients are usually between thirty and fifty years old. The tumour can spread to the joints and bones. Then it is very difficult to remove the tumor completely. In case of suspicion, x-rays and magnetic resonance examinations should be performed. The operation is the treatment of first choice. The removed tissue is typically yellow-brown to grey-white in colour with a flap-like and soft structure.