Hypercalcaemia as a manifestation of malignant urothelial change in analgesic nephropathy.

We report two cases of patients with analgesic nephropathy presenting with the symptoms of hypercalcaemia, and who were found to have transitional cell carcinomas of the renal pelvis. On removal of the tumours, calcium levels fell to normal, indicating that a humoral factor produced by the tumour caused the hypercalcaemia. We suggest that hypercalcaemia in a patient with analgesic nephropathy may indicate a malignant change, and that serum calcium should be assessed when such patients are reviewed.