A rare case of chronic lymphocytic leukemia with hypercalcemia induced by elevated parathyroid hormone-related peptides

Abstract

Hypercalcemia in malignancies is a frequent complication, mostly affecting patients with solid tumors or multiple myeloma. Calcium elevation is induced by direct bone infiltration of a tumor mass or through calcium liberation from the skeleton by a humoral mediator. The latter mechanism is referred to as humoral hypercalcemia of malignancy (HHM). Frequent mediators of HHM are parathyroid hormone-related peptides (PTHrP). We report a patient with chronic lymphocytic leukemia and hypercalcemia induced by PTHrP. In contrast to solid tumors and myeloma, PTHrP-induced HHM is very rare in low-grad lymphoma including chronic lymphocytic leukemia. Therapeutical approaches consist of cytoreductive treatment and calcium-lowering therapy with bisphosphonates.