Endocrine Abstracts

Introduction: Primary hyperparathyroidism JawTumor Syndrome is a rare genetic disorder characterized by the synchronous or metachronous occurrence of primary hyperparathyroidism and an ossifying fibroma of the maxilla and/or mandible, associated with an increased risk of parathyroid carcinoma.

Observation: We report the case of a 30-year-old young woman who consulted for a limp in walking,6 months after having been operated for a juvenile ossifying fibroma of the mandible. Standard X-ray showed multiple giant lacunar images at the level of the two iliac bones and the right femur, evoking brown tumours. A phosphocalcic assessment was requested showing a malignant hypercalcemia at 4.3 mmol/l, hypophosphatemia at 0.4 mmol/l, PTH=1360 pg/ml, PAL=900 IU/l, creatinine=85 µmol/l. Dual energy X-ray (DXA) showed osteoporosis at the neck of hip and 1/3 proximal of the radius. Cervical ultrasound and the SPECT-CT scintigraphy with 99m Tc-MIBI showed a 2.5×15 mm hypoechoic left subthyroidal formation with regular contours and hypervascularisation, no thyroid nodule, and no cervical adenopathies. The clinical picture was strongly suggestive of primary hyperparathyroidism in the context of jaw tumour syndrome. The abdomino- pelvic ultrasound was also performed, which showed no associated uterine polyps or tumours, nor renal tumors. The patient underwent a left inferior parathyroidectomy which was atypical in appearance. The histological examination revealed a parathyroid adenoma with no evidence of malignancy.

Conclusion: Primary hyperparathyroidism jaw -tumor syndrome is an entity that should be known given the association with malignant and atypical forms of parathyroid tumors of non-endocrine tumors that should be sought.