Paraneoplastic hypercalcemia with metastatic calcification--clinicopathologic studies

Hypercalcemia is a common paraneoplastic syndrome that may result in metastatic calcification. We report here on four autopsy cases with paraneoplastic hypercalcemia with metastatic calcification, to evaluate the clinicopathologic manifestations. All were males, aged 37-63 years old. Primary tumors included one transitional cell carcinoma of the urinary bladder, one multiple myeloma, and two squamous cell carcinomas of the esophagus. Calcium concentrations ranged from 3.3 to 5.9 mmol/L. Chronic hypercalcemia resulted in metastatic calcification. The kidney and stomach were the most vulnerable organs. Only case 1 presented with an increase in plasma calcium above 5 mmol/L (about twice the normal value); the metastatic calcification involved the capillary walls of his lungs, and he died of fulminant pulmonary edema. Our conclusion is that judicious treatment for paraneoplastic hypercalcemia is important with respect to the occurrence of pulmonary edema associated with metastatic calcification.