Serum calcium and phosphorus abnormalities in leukemia

The records of all cases of leukemia at the University of California Medical Center during the five year period from January 1960 to December 1964 were reviewed for data on serum calcium, phosphorus and alkaline phosphatase determinations and roentgenologic examination of the skeleton. A total of 260 cases were found, 123 of which included a calcium and phosphorus determination. Three patients (2.5 per cent) had hypercalcemia, and twenty-two (18 per cent) in whom renal function was not impaired had hyperphosphatemia. Increased alkaline phosphatase activity was found in 34 per cent of the patients tested. Hyperphosphatemia and increased alkaline phosphatase activity could not be correlated with other clinical or laboratory findings. Roentgenologic evidence of bone disease was found in eleven of twenty children examined, but in only ten of fifty-three adult patients. Seven cases of leukemia with hypercalcemia are reported. Six of the patients had acute leukemia; in the seventh case, however, the hypercalcemia was not related to the coexisting chronic lymphocytic leukemia. Symptoms of hypercalcemia preceded other evidence of acute leukemia in one case and in two reported previously. Early recognition of these cases is important since the hypercalcemia and its symptoms were reversed by corticosteroid therapy in all three instances. Roentgenologic evidence of bone disease was not always present at the time the hypercalcemia was discovered but usually appeared later. Serum phosphorus levels are usually normal or elevated in association with the hypercalcemia of leukemia, suggesting an osteolytic action other than that of parathyroid hormone. In one case of chronic lymphatic leukemia, hypercalcemia, hypophosphatemia and low tubular resorption of phosphate were corrected by removal of a parathyroid adenoma. In the first case, and in one reported previously, with hypercalcemia and hypophosphatemia, there was no evidence of parathyroid abnormality.