Serum parathyroid hormone levels in the hypercalcaemia of urological malignant disease.

Serum parathyroid hormone (PTH) levels have been measured in 8 patients with hypercalcaemia associated with urological malignancy: 3 renal cell carcinomas, 2 adenocarcinomas of prostate, 2 transitional cell carcinomas of bladder and one transitional cell carcinoma of kidney. Five (63%) of these 8 patients had bone metastases. PTH was detectable in the serum of all 8 hypercalcaemic patients, but in only 2 cases was the PTH level above the normal range, and in one of these a coincidental parathyroid adenoma was found to be responsible for the hypercalcaemia. It appears that these tumours can produce a hormone-like substance with biological effects similar to PTH.