Abstract

Paraneoplastic hypercalcemia is common, especially in advanced stage solid organ malignancies (breast cancer, renal cancer, lung cancer) and multiple myeloma, and is associated with poor prognosis. Paraneoplastic hypercalcemia is rarely observed in chronic lymphocytic leukemia. Due to its low incidence, there is not enough data in the literature about the effect of hypercalcemia on prognosis and its treatment. We reported this rare condition that a 68-year-old male who was followed up with a diagnosis of chronic lymphocytic leukemia and developed symptomatic malignant hypercalcemia. We concluded that ibrutinib was effective in the control of hypercalcemia due to chronic lymphocytic leukemia.