Endocrine Abstracts

Introduction: Successful parathyroid surgery in patients with OFC leads to early and marked improvements in BMD but data on very early changes in bone markers are missing.

Case report: A 20-year-old girl was hospitalised because of severe bone pains and multiple pathological fractures (left humerus and left proximal femur) after minimal trauma. She had lost weight, was amenorrhoeic for the last 12 months and was bleeding from brown tumours in her mouth. She was unable to walk and was complaining for general fatigue, anorexia, polyuria and polydipsia. Skeletal X-rays revealed multiple osteolytic lesions throughout the entire skeleton, brown tumours in the mandible and OFC change of the left shoulder. Serum calcium and PTH were of 14.7 mg/dl and 1243 pg/ml, respectively; alkaline phosphatase activity was 1372 U/l. After hydration with i.v. sodium chloride, the patient was given i.v. pamidronate (60 mg) and serum Ca fell to 12.4 after 2 days. The patient underwent parathyroid surgery and a right superior parathyroid adenoma (2.2 g) was removed. She was treated with oral calcium carbonate (2.4 g daily) and cholecalciferol 2000 U/daily. A marked reduction in BMD at LS (0.594 g/cm), FN (0.530 g/cm) and total body (0.680 g/cm) was seen by DXA, with T-scores in the markedly osteoporotic range (−4.9 and −3.9 S.D., respectively). After 9 months there were increases of 23.7, 39.6 and 31.2%, respectively; after 2 years of 44.1% (LS) and 64% (FN). In three other similar cases (OFC on X-ray) serum CTX decreased after 1 month by three to six times, while OC increased in one patient by 1.2 times and decreased in the other two by 90 and 53%, respectively. After 1 year CTX and OC were normal in the two patients with available data.

Conclusion: The cases show an unexpected rapid and profound decrease in resorbtion just 1 month after surgery while formation decreased at a much slower pace, changes that preceded the marked increase in BMD, especially at the cortical sites.