Hypercalcemia as the presenting feature of T-cell lymphoid blast crisis ofph-positive chronic myeloid leukemia

Hypercalcemia is a rare complication of chronic myeloid leukemia (CML), usu ally seen in the accelerated or blastic phases of the disease and associate d with a poor prognosis. T-cell lymphoid phenotype is also an infrequent fi nding in the blast crisis (BC) of CML. A CML patient who had hypercalcemia as the presenting feature of a T-cell BC is reported. She was a 78 year-old woman who, at four months of CML diagnosis, developed weakness, bone pain, and mental confusion. with hypercalcemia being subsequently found. Althoug h the peripheral blood and bone marrow were consistent with the chronic pha se of CML, mediastinal enlarge ment, a soft tissue mass adjacent to the ili ac bone, and multiple osteolytic lesions were seen. Serum levels of parathy roid hormone (PTH) and PTH-related peptide were normal, whereas the search for a second neoplasm was negative. The hypercalcemia initially responded t o conventional treatment, but it reappeared two weeks later. Coincidentally , a high proportion of blast cells of T-cell origin at the cortical thymocy te stage were observed in the patient's peripheral blood and bone marrow, a nd she died shortly afterwards.