FIBROUS DYSPLASIA OF BONE ASSOCIATED WITH PRIMARY HYPERPARATHYROIDISM

Objective: Fibrous dysplasia of bone and primary hyperparathyroidism (PHPT) may occur in patients with McCune-Albright Syndrome. A small number of cases with both diagnoses that are not associated with the above-mentioned genetic disorder have been published in the literature. It is uncertain if these disorders are linked in some way. In the present study, we aimed to further explore a potential relationship between PHPT and fibrous dysplasia of bone. Methods: We conducted a retrospective review of all cases seen at Mayo Clinic, Rochester, Minnesota, between 1976 and 2011 that were diagnosed with both PHPT and fibrous dysplasia of bone. Results: We identified 10 patients who were diagnosed with both PHPT and fibrous dysplasia of bone. Fibrous dysplasia was polyostotic in 7 (70%) cases. It affected the lower extremities in 6 (60%) patients, the skull or facial bones in 4 (40%), and was localized to one rib in 1 patient (10%). In 4 patients, fibrous dysplasia was diagnosed first, between 9 to 50 years before being diagnosed with PHPT. Two cases of fibrous dysplasia were recognized between 2 and 5 years after the diagnosis of PHPT. The remaining 4 patients were diagnosed with both conditions at approximately the same time. Conclusion: It remains unclear if the association between fibrous dysplasia of bone and PHPT is more than coincidental, although the possibility of a rare familial genetic syndrome is not completely excluded.