Hypocalciuric hyperparathyroidism with chronic renal failure

A patient with hypertension and chronic renal disease was evaluated for hypercalcemia and hypophosphatemia. Serum parathyroid hormone and urine nephrogenous cyclic adenosine monophosphate levels were both elevated. Absolute and fractional urine excretion of calcium was low, thereby raising the suspicion of hypocalciuric hypercalcemia. Surgical removal of a parathyroid adenoma led to normalization of the serum calcium, and phosphate values associated with the complete absence of calcium from the 24-hour urine collection returned to normal.