Answers to key questions about childhood leukemia--for the generalist

March 1, 2006

What goes wrong with blood cells and genes of children who suffer this grim disease? And how has a high cure rate revealed late effects of treatment? Answers to these (and more) questions shape your ongoing basic care of patients at the onset of, during, and after their illness.

Dr. Brown is an assistant professor in both the department of pediatrics at the Johns Hopkins University School of Medicine, Baltimore, Md., and the department of oncology at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore.

The word "leukemia," derived from Greek roots leukos ("white") and haima ("blood"), was first used in the medical literature in 1847 by Rudolph Virchow. In a paper with the title "Weisses Blut" ("White Blood"), Virchow described the autopsy case of a woman who had a massively enlarged spleen and pus-like masses in the blood vessels.

Yet the four decades that have passed since the Dorland's entry was published have been witness to remarkable progress in the treatment of leukemia, and it is pediatricians who have led the way in the unprecedented transformation of childhood leukemia from universally fatal illness to one that is curable in approximately three of every four cases.

To the next question!

Is leukemia common?

How is it classified?

The first level of classification of leukemia divides cases into acute and chronic. Acute leukemia is characterized by the predominance of highly immature WBC precursors, or blasts. Left untreated, it is an aggressive, rapidly fatal disease. Chronic leukemia is characterized by proliferation of relatively mature WBCs. It is typically an indolent disease.

The second level divides cases into lymphoid and myeloid types, depending on whether leukemic cells display characteristics of lymphocyte precursors or myelocyte (granulocyte, erythrocyte, monocyte, megakaryocyte) precursors. The four major types of leukemia are, therefore: