Tumoral calcinosis is a rare disorder characterised by calcification of periarticular soft tissue. Although hyperphosphatemia is not always accompanied, it is thought to be a pathogenetic factor. We report such a rare case of tumoral calcinosis in a 17-year-old girl. She had a gradually enlarging mass on her back near the right scapula. Plain radiograph computed tomography, and magnetic resonance imaging revealed a partially calcified lesion between the right scapula and thorax. Laboratory tests including the levels of serum calcium and parathyroid hormone (PTH) were normal, except for increases in serum phosphorus (5.7mg/dl) and slight increases in 1, 25 (OH)2 Vitamin D and calcitonin. The tubular reabsorption of phosphate was increased. High-dose PTH infusion increased urinary phosphorus and cyclic AMP excretion so that renal tubular reabsorption due to exogenous PTH was adequate. The pathogenesis of this disorder should be evaluated further from the aspect of mineral metabolism.
