Fibrous dysplasia of ethmoid.

FIBROUS dysplasia is a peculiar clinical entity, which is of interest to the Otolaryngologist, because at times it involves one of the paranasal sinuses. Fibrous dysplasia of the bone is the name applied by Lichtenstein (1938) to a polyostotic or monostotic condition apparently due to a perverted activity of the specific bone-forming mesenchyme. It is most frequently localized in the femur, tibia, rib, maxilla and mandible. Among the extra-skeletal aspects of the condition, abnormal pigmentation of the skin, premature sexual development in females and signs of hyperthyroidism have been described in very severe conditions.