Metastatic calcinosis is a common feature of chronic renal failure. Its first manifestations are bone demineralization and non-visceral and/or visceral calcification with mostly mural deposits in arteries and arterioles. It is initially characterized by hyperphosphataemia followed by secondary or tertiary hyperparathyroidism. Cutaneous involvement is a rare complication. Histologically, the lesions show vascular calcification with ischaemic skin necrosis. Extreme cases may produce calcinosis cutis (calciphylaxis), i.e. disseminated calcification of the subcutaneous tissue and dermis in the form of hard painful cutaneous nodules and plaques with subsequent ulceration. Metastatic calcinosis is a disease affecting adults, while the dystrophic or idiopathic type can develop in children. We present the case of a 6-year-old boy with end-stage renal disease, attributed to congenital renal hypoplasia, and accompanied by secondary hyperparathyroidism. He developed fulminant tertiary hyperparathyroidism and metastatic calcinosis of the lungs, as well as cutaneous necrosis of the buttocks and legs, subsequent to calcification of arteries and arterioles. A maternal renal transplant failed to function. The serum parathormone, calcium and phosphate levels could not be controlled by maintenance dialysis, phosphate binders and calcitriol. Total parathyroidectomy without autotransplantation of parathyroid tissue rapidly returned the serum parathormone, calcium and phosphate levels to normal. In addition, topical treatment using merbromine solution and hydrocolloid dressings, healed the ulcers with significant scar formation, within 2.5 months after parathyroidectomy. A renewed increase of the calcium x phosphate product, 2 months after parathyroidectomy, was attributed to mobilization of calcium compounds from the viscera, as confirmed by a chest X-ray.

The pathogenesis of calciphylaxis, a potentially life-threatening condition, is not well understood. Several factors such as end-stage renal disease (azotemia), hyperparathyroidism, hyperphosphatemia, hypercalcemia, a high calcium-phosphate product, and the use of steroids and cytotoxic drugs after kidney transplantation are believed to interact in calciphylaxis. Recently, hypercoagulability due to functional protein C deficiency has been suggested to play a pathogenic role in this condition. Here, we present a renal transplant patient, with secondary hyperparathyroidism and on long-term oral anticoagulant therapy, who developed calciphylaxis with severe skin necrosis of her legs. The patient’s condition improved dramatically after total parathyroidectomy. Hypercoagulability, therefore, does not appear to have played a significant role in this case of calciphylaxis.

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