[A rare cause of bone pain in children: primary hyperparathyroidism caused by adenoma]

Primary hyperparathyroidism is rare in children and adolescents. Bone changes may produce pain in the back or extremities, but this is rarely the first symptom of the disease.

A 13 year-old girl suffered from pain in the back and lower extremities. Progressive bilateral genu valgum appeared. One year later, she became lame because of the deformity. ECG showed cardiac arrhythmia with atrial extra systoles. The serum calcium concentrations were 3.36 and 3.8 mmol/l, phosphate 0.76 mmol/l and alkaline phosphatases 6,612 U/I (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 revealed resorption of subperiosteal bone, best seen along the margins of the 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 heterogeneous mass, 23 x 15 mm, suggesting a parathyroid adenoma. This adenoma was independent of the left inferior parathyroid. It was removed and the biochemical findings gradually returned to normal. Bone demineralization also disappeared and the knee deformities were surgically corrected 9 months later.

Bone changes may occasionally cause severe pain, indicating demineralization and hypercalcemia: hyperparathyroidism is one cause of such changes.