Tumor lysis syndrome in a chronic lymphocytic leukemia patient with pleural effusion after oral fludarabine and cyclophosphamide therapy.

Tumor lysis syndrome (TLS) is a rare complication of the treatment for chronic lymphocytic leukemia (CLL). Since the advent of new therapeutic agents with higher response rates, however, TLS has been observed with increasing frequency. An 84-year-old woman with a nine-year history of untreated CLL presented with exacerbating dyspnea due to pleural effusion. CLL cells without Richter transformation were observed in the pleural effusion at a high concentration, as well as in lymph nodes and bone marrow. After 5 days of oral fludarabine and cyclophosphamide (FC) therapy, the patient developed TLS, which necessitated rescue with hemodialysis. Although transient exacerbation of pleurisy occurred, the effusion cytology ameliorated, and she eventually achieved complete remission after additional two courses of FC and rituximab. Sequestration of fludarabine in the pleural effusion may be attributable to the development of TLS.