We have found in the literature twelve cases of histologically benign giant-cell tumor (osteoclastoma) associated with Paget's fibrous osteitis deformans. To this we have added our own case in which the tumor was localized in the diaphysis of the tibia in a monostotic lesion in a patient, forty-five years old, who was followed for more than four years from the beginning of the disease.
This type of tumor has a marked predilection for the bones of the skull and face, in direct contrast to the usual location of the genuine giant-cell tumor originating in bones unaffected by Paget's disease. Ours is the third case in the literature of localization in a long bone, and the second in the tibia. Conservative treatment was used and, following two local recurrences, the tumor was treated again with a wider resection.
The prognosis of the giant-cell tumor complicating Paget's disease is generally favorable, whereas a sarcoma growing in a bone affected by Paget's disease is rapidly fatal.
Therefore, recognition of the lesion and its histological diagnosis before beginning treatment is extremely important.