Introduction:
Hyperparathyroidism-Jaw Tumour Syndrome (HPT-JT) is a rare, autosomal-dominant condition caused by inactivating mutations of the CDC73 gene which encodes the protein parafibromin1. It is characterised by hyperparathyroidism, ossifying fibromas of the maxilla and mandible; and lesions of the kidneys and uterus2. Penetrance is high with most developing hyperparathyroidism before age 503.
Case report:
A 35 year old lady was referred for assessment of primary hyperparathyroidism (Figure 1). Her main symptoms were lethargy and thirst. There was a past history of wrist fracture in her 20’s and previous fibroid removal. She had no regular medications. She had 3 children with un-complicated pregnancies. Examination revealed no palpable neck masses or signs of hormonal deficiency, excess or a specific endocrine syndrome. Interestingly, she had a strong family history of parathyroid disorders. Her paternal grandfather had hyperparathyroidism; paternal uncle had parathyroid carcinoma and a paternal cousin had parathyroidectomy for unknown reasons.
She was referred for parathyroidectomy and a large parathyroid adenoma was excised. Immunohistochemistry staining for parafibromin was negative. Genetic testing confirmed our patient carried a germline mutation in CDC73 diagnostic of HPT-JT.
OPG and renal ultrasound were normal. Pelvic ultrasound revealed a lower uterine mass 40x30x30mm. She underwent hysterectomy and bilateral salpingectomy which revealed a cervical adenosarcoma. Histological margins were intact and there was no lymphovascular invasion. The adenosarcoma stained negative for parafibromin confirming its relation to HPT-JT.
One year post-parathyroidectomy our patient’s calcium and PTH levels remain normal. One of her children also tested positive for CDC73 mutation. Both our patient and her child undergo regular monitoring with blood tests, OPG and ultrasounds of the kidneys and pelvis.
Conclusion:
HPT-JT is a rare disorder characterised by hyperparathyroidism and lesions of the jaw, kidneys and uterus. Regular biochemical and radiological monitoring is crucial for the ongoing management of patients with this condition.