Abstract
1. Four cases of polyostotic fibrous dysplasia are presented.
2. All are males, all show cutaneous pigmentation, and in two there has been precocious puberty.
3. The literature has been reviewed, and present conceptions of the pathology and etiology of the disease have been discussed.
4. The dysplasia if often confused with parathyroid osteodystrophy and sometimes the parathyroid glands are needlessly explored. This confusion should not arise if it is remembered that no general skeletal decalcification, and no constant changes in the blood calcium or phosphorus, occur in polyostotic fibrous dysplasia. The radiographic appearances of healing parathyroid osteodystrophy are, however, indistinguishable.
5. No effective therapy has been discovered for this disease. Pathological fractures and deformities may require treatment.