Fibrous dysplasia of bone associated with primary hyperparathyroidism

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.

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.

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.

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.