Second neoplasms in patients with chronic lymphocytic leukemia.

Second malignancies occur with increased frequency in patients with chronic lymphocytic leukemia (CLL) regardless of treatment, but they may be more frequent and more aggressive after nucleoside analog therapy of CLL. In as many as 33% of patients with CLL who develop a second malignancy, a spontaneous remission of CLL precedes the diagnosis of the second malignancy by months or years. Richter's syndrome, whether manifested by anaplastic large cell lymphoma or Hodgkin's disease, is not truly a second malignancy because the CLL clone appears to be involved. However, all other malignancies developing in patients with CLL appear to be derived from a different clone. CLL and the second malignancy may have a common viral etiology. Second malignancies in patients with CLL should be treated as they would be in patients without CLL.