Massive Soft Tissue Calcifications and Cinacalcet

Abstract

A 37-yr-old man on long-term hemodialysis developed a relapse of secondary hyperparathyroidism after subtotal parathyroidectomy. Dialysis treatment adjustment and conventional medical therapies, involving noncalcium phosphate binders and active vitamin D sterols, proved ineffective. Painful and rapidly increasing tumor-like masses appeared over the second finger and the back of his right hand. Laboratory studies showed persistent serum levels of intact PTH of more than 1500 pg/ml and calcium-phosphate product of more than 100 mg/dl [recommended levels in dialysis patients, 150–300 pg/ml (16.5–33 pmol/liter) and 55 mg/dl, respectively] (1). A radiograph of the right hand revealed massive soft tissue swelling and calcifications (Fig. 1). Due to the patient’s disinclination for further surgical treatment, we decided to administer cinacalcet (2, 3), a calcimimetic agent, at doses of 30–60 mg/d, achieving a significant suppression of intact PTH (350 pg/ml) and calcium-phosphate product (60 mg/dl). After correction of the calcium-phosphate product, oral calcitriol and calcium acetate were administered. Six months later, a radiographic control showed the disappearance of the calcifications (Fig. 2). Massive soft tissue calcification is a feature of severe renal hyperparathyroidism and is due to chronic elevation of calciumphosphate product, resulting in the precipitation of calcium phosphate. The calcified masses should not be misdiagnosed as tumors and surgically excised, because they will recur unless the biochemical abnormalities are corrected (4). High serum calcium and phosphate levels may also cause disseminated calcification in the skin, joints, viscera, and arteries (calciphylaxis) resulting in painful ischemic necrosis of skin and gangrene, cardiac arrhythmias, and pulmonary failure. Uncontrolled hyperphosphatemia and progressive metastatic calcifications have always been indications for surgical parathyroidectomy (5). When conventional therapies have been exhausted, cinacalcet represents an exceptional therapeutic opportunity particularly for patients exposed to technical difficulties linked to a neck re-operation (3).