Chronic leukemias.

Chronic leukemias include a broad spectrum of disorders generally characterized by uncontrolled proliferation of mature, differentiated cells of the hematopoietic system. Clinical manifestations and treatment strategies vary widely among the disorders. In some cases, immediate aggressive treatment is required; while in others, it is more appropriate to withhold immediate treatment and perhaps not treat at all. This article reviews the pathologic features, clinical characteristics, and treatment of chronic leukemias.