[Altered calcium-phosphorus metabolism and low-protein diet]. / Alterazione del metabolismo calcio-fosforo e dieta ipoproteica.

Many metabolic disorders associated with uremia can affect the long-term survival of patients with chronic kidney disease. Such disorders can be defined as: hypocalcemia, increased levels of phosphorus, reduced synthesis of 1,25-dihydroxyvitamin D and serum calcitriol, and reduced expression of vitamin D receptors on parathyroid cells with increased parathyroid hormone levels and secondary hyperparathyroidism. Phosphorus, which plays a crucial role in the progression of progressive renal disease, has been shown to be an independent risk factor for death in hemodialysis patients. Thus, reducing the phosphorus intake by decreasing dietary proteins may slow the progression of renal disease. Hypocalcemia is typically associated with chronic kidney disease. It is due to the reduced intestinal absorption of calcium and the spontaneously reduced protein intake that occur in patients with progressive renal disorders. Activated vitamin D and calcium supplements should be administered to patients who are following low-protein diets to prevent secondary hyperparathyroidism; the doses should be correlated with actual renal function and protein intake.

Tumoral calcinosis. Case report with treatment failure.

Periarticular calcifications are the hallmark of a rare entity: tumoral calcinosis. We have followed for 90 months a nine-year-old black girl with involvement of both shoulders. Seven initial local excisions of the mass on the right shoulder were attempted without complete removal and prompt recurrence after each attempt. The entire lesion on the right side, including a cutaneous ulceration, was managed by en masse surgical excision. Preoperative inpatient medical management in the form of low calcium and low phosphorus diet was unsuccessful. Postoperatively, she has remained free of ulceration; however, after two and a half years, the right mass has again increased in size with compression of the brachial plexus. This recurrence occurred despite strict dietary control starting immediately postoperatively. Although there are many advocates of surgical excision of these lesions and, more recently, several cases reported of successful medical management, we find that often a combination approach is necessary to effectively treat tumoral calcinosis and reduce the rate of recurrence.