Primary hyperparathyroidism and chronic lymphocytic leukemia.

Although hypercalcemia is a frequent event during the course of many malignancies it has only rarely been described with patients with chronic lymphocytic leukemia. Review of the literature revealed only eleven such case reports. The mechanism of the hypercalcemia in these patients was generally unclear although one patient was found to have a parathyroid adenoma and in another patient tested the level of osteoclast activating factor was high. Two additional chronic lymphocytic leukemia patients with hypercalcemia are described in this report and in each a parathyroid adenoma was found. The patient in whom the diagnosis was made ante mortem had an excellent response to parathyroidectomy. Osteoclast activating factor level was measured in one patient and found to be within normal limits. Since three of the thirteen reported cases of chronic lymphocytic leukemia with hypercalcemia have demonstrated parathyroid adenomas, it is suggested that consideration be given to that possibility in such patients so that appropriate surgery may be done.