[Extreme hyperphosphatemia with hypocalcemia within the scope of cell lysis syndrome in a child with T-ALL].

In a 10 3/4-year-old girl suffering from a T-ALL with an extremely high leukocyte blood cell count (400,000/microliters) we observed a tumor-lysis syndrome with hyperphosphatemia and hypocalcemia accompanied by clinical signs of tetany. The therapeutic application of calcium gluconate resulted in vascular calcification by exceeding by far the calcium-phosphate solubility product. The fast lysis of T-lymphoblasts with their high phosphate concentration is etiologically involved in the hyperphosphatemia. Our patient died of multiorganic failure. Regular monitoring of phosphate in urine might be helpful in instituting early therapeutic procedures.