Sodium thiosulfate in the treatment of tumoral calcifications in a hemodialysis patient without hyperparathyroidism.

Extraskeletal tumoral calcifications (TC) may occur in patients with end-stage renal disease. The TC usually develop in the presence of secondary hyperparathyroidism or a high calcium x phosphate product, while other factors have been also occasionally implicated in their development. At present, no uniformly accepted effective treatment has been described for this condition. We describe a 58-year-old female patient with end-stage renal disease who 7 years after the onset of dialysis presented with pain and movement restriction of various joints. A skeletal X-ray showed huge amounts of periarticular TC. The TC occurred in the absence of hyperparathyroidism or a high calcium x phosphate product as evidenced by hormonal and biochemical examination as well as by a bone biopsy specimen that revealed an adynamic bone disease with significant aluminum staining. Sodium thiosulfate, an inorganic salt that has been claimed to inhibit the formation and to favor the solubility and the mobilization of calcified masses, was administered to the patient, and after a long period of treatment considerable radiological regression of the TC with concurrent clinical recovery was noticed. Aluminum intoxication, along with other factors, was considered to be the cause of TC development. The use of sodium thiosulfate seemed to be a reasonable nonspecific therapeutic approach for the management of TC in this case.