The pathogenesis of chronic lymphocytic leukemia.

The pathogenesis of chronic lymphocytic leukemia was examined in a series of 88 cases observed during a 15-year period. In untreated cases the trend of the absolute lymphocyte counts followed two main patterns. In the type I trend, the counts rose throughout the observation period; in the type II trend, the tendency to rise ceased and the counts stabilized above and below a mean value, the stationary trend being maintained for months or years. The type II trend was associated with relatively benign disease. The development of lymphocytosis was correlated with the progression of lymphadenopathy. It is suggested that lymphocytosis may result from the physiological process of recirculation and that the accumulation of lymphocytes may result from the proliferation of a single slightly abnormal cell-line. The abnormal cells might survive an unusually long time because they are unable to respond to stimuli which cause normal lymphocytes to transform.