Background: Derangements in bone mineral metabolism are an invariable consequence of end-stage renal disease (ESRD). Extraosseous tumoral calcification is a relatively uncommon complication that can be associated with substantial morbidity.
Methods: The authors report a case of an ESRD patient who had severe tumoral calcification of his shoulder, hands, and feet despite daily conventional hemodialysis. Conversion to daily nocturnal hemodialysis (DNHD) led to a dramatic resolution of his calcific deposits within only 9 months of initiating this form of renal replacement therapy.
Results: After initiating DNHD, the patient's serum phosphate level, which had been exceedingly difficult to control, normalized within the first week. Despite maintaining a high dialysate calcium (Ca) bath up to 4.2 mEq/L (2.1 mmol/L; to maintain calcium balance and suppress parathyroid hormone [PTH]), there was ongoing dissolution of the calcific deposits. This occurred with relatively preserved bone mineral density. The Ca x phosphorus (PO4) product decreased from 85 mg2/dL2 (6.80 mmol2/L2) and remained less than 55 mg2/dL2 (4.4 mmol2/L2) throughout the patient's course on DNHD. PTH levels fell precipitously early on but then rose again several months after starting DNHD. This PTH rebound as well as the possible mechanisms underlying the dissolution of this patient's extraosseous calcifications are explored further.
Conclusion: Extraosseous tumoral calcification associated with ESRD is an uncommon but potentially serious complication in this patient population. DNHD, by offering superior phosphate clearance, can facilitate the dissolution of these calcific deposits over a relatively short period. This effect can be seen despite using high calcium concentration dialysate to maintain calcium balance and mitigate hyperparathyroidism.
Copyright 2003 by the National Kidney Foundation, Inc.