Detection and pathogenesis of visceral calcification in dialysis patients and patients with malignant disease.

Scintiscanning to detect the uptake of bone-seeking radioactive isotopes by soft tissue is a promising technique for the in vivo study of visceral calcification. Visceral uptake of such radioisotopes was studied in 40 patients: 22 undergoing long-term dialysis, 9 with malignant disease and hypercalcemia and 9 with primary hyperparathyroidism and hypercalcemia.Fifteen patients, 11 undergoing dialysis and 4 with malignant disease, had radioisotope uptake in the lungs, and 5, 3 undergoing dialysis and 2 with malignant disease, had uptake in the stomach. None of the patients with primary hyperparathyroidism had visceral uptake, nor did the patients with uptake have radiologic evidence of pulmonary or gastric calcification. The dialysis patients with visceral uptake had a mean calcium x phosphate product of 84.3 +/- 23.7 (standard deviation), which was significantly greater (P < 0.001) than that of patients without such uptake (59.2 +/- 14.0). Similarly, in patients with malignant disease and visceral uptake the Ca x P product was 72.2 +/- 6.4 - significantly greater (P < 0.005) than that of patients without such uptake (49.3 +/- 6.7).These findings indicate that scintiscanning for the visceral uptake of a bone-seeking radioisotope is a simple and effective technique for the in vivo study of visceral calcification. An elevation in the Ca x P product seems to be the single most important factor in the production of visceral calcification.