Fibrous dysplasia associated with primary hyperparathyroidism in the absence of the McCune-Albright syndrome: Tc-99m MIBI and Tc-99m MDP findings

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.

False Positive FDG PET/CT Resulting from Fibrous Dysplasia of the Bone in the Work-Up of a Patient with Bladder Cancer: Case Report and Review of the Literature

Fibrous dysplasia of the bone (FDB) is a common, genetic, developmental disorder with a benign course. FDB can be seen anywhere throughout the skeleton. It is usually asymptomatic and found incidentally on imaging studies that are performed for other purposes. Although whole body 18 F-flourodeoxyglucose PET/CT (FDG PET/CT) is widely used in tumor imaging, infections and benign pathologies like FDB may cause false positive results. Herein we report the case of a 48-year-old FDB patient with transitional cell carcinoma of the urinary bladder. Restaging FDG PET/CT showed multiple mild to moderate hypermetabolic bone lesions which were initially misinterpreted as bone metastases. In this case report, we aimed to guide physicians in evaluating bone lesions in cancer patients with FDB in the light of the literature.

The role of dual-phase Tc-99m MIBI in the evaluation of potentially operable lesions detected by bone scanning in fibrous dysplasia: a long-term prospective follow-up study

PURPOSE

The aim of this study was to determine the role of whole-body Tc-99m MDP bone scintigraphy (BSc) with dual-phase Tc-99m MIBI scintigraphy (DPMSc) in the assessment of fibrous dysplasia (FD) and the value of DPMSc in the detection of potentially operable lesions for guiding surgical treatment.

METHODS

Twelve patients with histopathologically confirmed FD were evaluated with BSc and DPMSc. The patients were clinically followed up for a mean duration of 75 months. BSc images have been used as a guide to identify the site and the extent of the skeletal involvement. The symptomatic lesions were evaluated with DPMSc.

RESULTS

Forty-three lesions were evaluated in 12 patients. BSc showed increased uptake in all of the lesions, whereas DPMSc findings correlated more accurately with the symptoms. Fifteen symptomatic lesions showed increased Tc-99m MIBI uptake on DPMSc, especially in the early phase of DPMSc. The sensitivity, specificity and accuracy values for the early phase in detecting the symptomatic lesions were 100 and 93%, and for delayed phase were 100 and 98%, respectively.

CONCLUSION

BSc is useful in determining the site and extent of the skeletal involvement, especially in polyostotic FD. It seems that the potentially operable symptomatic lesions may be evaluated more accurately with DPMSc as compared with BSc. In addition, it seems that DPMSc findings correlate with the symptoms of FD, and this relationship may have a role in improving the preoperative assessment for guiding surgical treatment. DPMSc could be useful in the work-up of symptomatic patients if our results are validated in a larger patient series.

Analysis of GNAS mutations in cemento-ossifying fibromas and cemento-osseous dysplasias of the jaws

OBJECTIVES

It is well established that fibrous dysplasia (FD) is caused by mutations of the Arg(201) codon of the GNAS gene. However, the role of GNAS mutation in the pathogenesis of cement-osseous dysplasias (COD) and cemento-ossifying fibromas (COF) is not fully known. In this study, we examined COD and COF for mutations at the Arg(201) codon of the GNAS gene.

STUDY DESIGN

The study sample included formalin-fixed, paraffin-embedded tissue blocks from 8 COF and 24 COD. We used 2 PCR-RFLP methods to detect mutations at the Arg(201) codon of the GNAS gene.

RESULTS

Mutations at the Arg(201) codon of the GNAS gene were not present in any of the COD and COF examined.

CONCLUSIONS

GNAS mutations do not play a role in the pathogenesis of COD and COF. This highlights a clear molecular distinction between FD and other histologically similar fibro-osseous lesions of the jaws.