A RARE CAUSE OF BONE PAIN IN CHILDREN - P RIMARY HYPERPARATHYROIDISM DUE TO AN ADENOMA

Background. Primary hyperparathyroidism is rare in children and adoles cents. Bone changes may produce pain in the back or extremities, but t his is rarely the first symptom of the disease. Case report. A 13 year -old girl suffered from pain in the back and lower extremities. Progre ssive bilateral genu valgum appeared. One year later, she became lame because of the deformity. ECG showed cardiac arrythmia with atrial ext ra systoles. The serum calcium concentrations were 3.36 and 3.8 mmol/l , phosphate 0.76 mmol/l and alkaline phosphatases 6 612 U/l (N: 90-300 ). Urinary excretion of calcium was 17 and 26 mg/kg/day and the renal tubular reabsorption of phosphate was 77%. Radiological studies reveal ed resorption of subperiosteal bone, best seen along the margins of th e phalanges, demineralization of the skull vault, bilateral coxa vara and zones of calcification on knee metaphyses. The serum concentration of parathyroid hormone (PTH) was 1 066 pg/ml (N: 10-55) and that of 1 -25(OH)2D3 was 125 ng/ml (N: 20-80). Ultrasonography showed a heteroge neous mass, 23 x 15 mm, suggesting a parathyroid adenoma. This adenoma was independant of the left inferior parathyroid. It was removed and the biochemical findings gradually returned to normal. Bone deminerali zation also disappeared and the knee deformities were surgically corre cted 9 months later.Conclusions. Bone changes may occasionally cause s evere pain, indicating demineralization and hypercalcemia: hyperparath yroidism is one cause of such changes.