Acute tumor lysis syndrome in prolymphocytic leukemia.

Prolymphocytic leukemia is characterized by a low response rate to agents that are effective in the treatment of chronic lymphocytic leukemia. A 75-year-old man with prolymphocytic leukemia was followed up over a period of 69 months. During that time, he was treated with high-dose chlorambucil plus prednisone; cyclophosphamide administered daily; combinations of vincristine sulfate, prednisone, and cyclophosphamide; irradiation to the spleen; and alpha-interferon without substantial antitumor effect. The patient had a brief response after splenectomy. When he received low-dose vincristine therapy daily with high-dose prednisone therapy given on alternate days, a fatal tumor lysis syndrome occurred. Although rare, this complication should be kept in mind, particularly in patients who had rapid reduction of tumor cells.