RESUMO
A 64-year-old woman is reported with Stage I (Rai) chronic lymphocytic leukaemia (CLL), in whom hypercalcemia developed when an increased proportion of prolymphocytic cells characterized a transformation of CLL in prolymphocytoid leukaemia (CLL/PL). Although hypercalcemia is more frequently found in T-cell leukaemia associated with human T lymphotropic lymphocyte type I, scattered reports indicate that patients with B-CLL can also be affected with this metabolic disturbance. The case described here, progressed with an indolent course of CLL for 26 months, when she was admitted with a very aggressive disease characterized by a high WBC count, splenomegaly and hypercalcemia. Despite an effort to achieve a clinical remission, she failed treatment and death was attributed to unresponsive hypercalcemia. The mechanism of hypercalcemia in such cases is unclear as no parathyroid adenoma or second malignant tumor was found ante mortem. This electrolytic disturbance would appear to be a direct consequence of the transforming leukaemia and a possible mechanism involving a secreted humoral factor that could lead to altered calcium metabolism.