Endocrine Abstracts

Introduction: Manifestations of primary hyperparathyroidism (PHPT) such as osteoporosis and stone diseases are common primary diagnostic findings beyond a hypercalcemia. Classical skeletal involvement can be the first sign of PHPT, but not recognized because osteitis fibrosa cystica (bone cysts, brown tumors of the long bones) is rarely seen today in Western Europe.

Case report: A 34-year old women from Afghanistan was presented to our out-patient-clinic with a history of chronic back and joint pain, as well as numbness and parasthesia in both arms and legs. Previously she was referred to orthopedic surgery, neurosurgery and neurology for further investigations. MRI showed multiple intraosseous cystic lesions in the pelvis and multiple ribs. DXA confirmed osteoporosis (lumbar spine T-score: −4,6; total hip T-score −4,1). Biochemical evaluation revealed hypercalcemia of 2.81 mmol/l (ref. range 2.09–2.54), hyophosphatemia of 2.53 mg/dl (2.6–4.5), 25-OH Vitamin D of 26 ng/ml (20–70) under supplementation and elevated parathyroid hormone of 571 pg/ml (15–65). Blood and urine creatinine were normal. Ultrasound of the neck showed hyperplasia of all four parathyreoid glands. Multiple endocrine neoplasia 1 and malignancy of cystic pelvic lesions were excluded. By parathyreoidectomy two cranial parathyroid adenomas were removed. Caudal no adenoma could be identified during surgery. Immediately after surgery the parathyroid hormone decreased >50%. At the follow-up visits the patient showed a good improvement of her symptoms without developing a hungry-bone-syndrome.

Conclusion: The case shows the rare presence of osteitis fibrosa cystica as a clinical manifestation of a PHPT. It emphazises the importance of an early diagnosis of PHPT with a detailed diagnostic workup, including imaging and biochemical investigations of bone metabolism. When radiographic evidence of a lytic lesion and hypercalcemia are present, PHPT should always be considered in the differential diagnosis.