Juvenile features in adult-type chronic granulocytic leukemia

Philadelphia chromosome (Ph1) positive, or "adult-type," chronic granulocytic leukemia (CGL) differs in many clinical and laboratory aspects from PH1-negative, or "juvenile," CGL. Because of these differences, the disorders have been considered two distinct disease entities. We present a child with Ph1-positive CGL whose disease has several features more characteristic of the Ph1-negative syndrome. This case demonstrates that the chromosomal anomaly in CGL is not always predictive of phenotypic expression in this disease.