Hypercalcemia complicating a megakaryoblastic crisis of chronic myelocytic leukemia.

A 38-year-old woman with megakaryoblastic chronic myelocytic leukemia (CML) crisis developed recurrent episodes of severe hypercalcemia, manifested by nausea and vomiting and later by dyspnea and hypoxia. The levels of serum parathyroid hormone and serum and urine cyclic AMP were normal. Autopsy revealed widespread metastatic calcifications in various organs, including the lungs. The case suggests that hypercalcemia complicating blast crisis of CML is not related to blast cell phenotype, can cause severe pulmonary malfunction, and is a terminal event. The hypercalcemia most probably resulted from bone resorption, either directly by the megakaryoblasts or by secretion of osteolytic substances.