Uremic tumoral calcinosis in patients receiving longterm hemodialysis therapy

Objective. To analyze a series of uremic tumoral calcinosis (UTC) in patients receiving longterm dialysis therapy. Methods, Twelve patients receiving longterm hemodialysis affected by tumoral calcinosis were analyzed, Clinical, radiological, and pathological features were evaluated and pathogenic factors were reviewed. Results, The most common sites for UTC were the elbow, hip, hand, and wrist. The lesions were multiple (67%, n = 8), of large size, and symptomatic with joint mobility impairment (75%, n = 9) as well as nerve compression (33%, n = 4). High serum calcium and phosphate concentrations were detected in 50% (n = 6) and 100% of the patients, respectively. An increased calcium-phosphorus product (Ca x P) was observed in all patients, either due to overt secondary hyperparathyroidism (42%, n = 5), or secondary to iatrogenic hypercalcemia and/or severe hyperphosphoremia of multifactorial etiology (i.e., prolonged and excessive administration of calcitriol and calcium carbonate, insufficient dialysis and inadequate phosphorus chelating therapy, etc.) (58%, n = 7). Several treatment strategies were followed (surgical excision, parathyroidectomy, renal transplant) in combination with aggressive medical therapy to decrease Ca x P product, achieving complete remission in 83% of the patients. Conclusion. UTC lesions show clinical and pathogenic features that differ from those of idiopathic tumoral calcinosis. The most important pathogenic factor involved in UTC is an increase in Ca x P, not necessarily related to hyperparathyroidism. Combined treatment strategies allow complete remission in a high proportion of patients. A low Ca x P is necessary to prevent development of UTC.