Endocrine Abstracts

Introduction: Primary hyperparathyroidism is associated with multiple complications: severe bone disease is one of them. Osteomalacia is by definition a metabolic bone disease characterized by a softening of the bones. We herein report a rare case of an association between primary hyperparathyroidism with osteitis fibrosa cystica and osteomalacia caused by a severe vitamin D deficiency.

Observation: A 37-year old woman was referred for investigation of weakness and loss of autonomy. She complained of generalized muscular and bone pain, height and weight loss for 1 year. On physical examination, she had waddling gait and hourglass chest deformity. X-ray examination showed looser zones at the pelvis, osteopenia and an aspect of osteitis fibrosa cystica. Computed tomography showed a brown tumor at the right ilium. The patient was diagnosed with primary hyperparathyroidism based on increased serum calcium 2.7 mmol/l (normal range: 2.20-2.60), increased parathormone concentration 2504 pg/ml (normal range: 15-72) and a low serum phosphate 0,67 mmol/l (normal range:0.80-1.45). The urinary calcium was 0.08 mmol/kg/24h. Renal ultrasonography showed a bilateral nephrolithiasis and BMD showed osteoporosis with a high fracture risk: lumbar T-score -5.3 and Hip T-score -4. The diagnosis of osteomalacia was based on clinical and radiological presentation, low 25-OH vitamin D 3.28 ng/ml and elevated phosphatase alkaline 4590 UI/l (normal range <240). Cervical ultrasonography showed a 25x17 mm hypoechoic mass below the left lobe of the thyroid. Parathyroid scintigraphy confirmed increased uptake in the topography of left inferior parathyroid gland. The patient received vitamin D and calcium supplementation and therefore underwent a left lower parathyroidectomy. Postoperative pathology confirmed the diagnosis of parathyroid adenoma. The intraoperative serum PTH concentration was 106 pg/ml. She had hypocalcemia on the third day after surgery: the serum calcium concentration was 1.9 mmol/l. She recovered well after calcium supplementation and was discharged 1 week after surgery.

Conclusion: This case report illustrates a rare case of a severe bone disease caused by an association of a chronic primary hyperparathyroidism and osteomalacia. Prevention, diagnosis and treatment of vitamin D deficiency and the early diagnosis of primary hyperparathyroidism are very important.Key words Primary hyperparathyroidism-bone disease-osteomalacia-vitamin D deficiency-case report