Acute lymphoblastic leukemia (ALL) in adults is a relatively rare disease, comprising approximately 20% of the acute leukemias in patients above 15 years of age.16 ALL is more common in children, comprising nearly 90% of the acute leukemias in patients under age 15 (Table 4–1). Many of the advances in the understanding of ALL and in the clinical management of the illness have been made by studying the pediatric population. Nevertheless, the approach to the disease in adults is quite similar, and today the possibility of cure of ALL has been realized in both the pediatric and adult populations.