The significance of the subclassifications of acute lymphoblastic leukemia

The development of new methodologies in cellular immunology, enzymology, and cytogenetics as well as the detailed analysis of patient characteristics in long-term clinical studies have facilitated the subclassification of ALL in ways that ultimately will prove to be beneficial to children with this disease by extending survival and improving overall cure rates. At present, the distinction of T cell leukemia is recognized as necessary for its optimal treatment, and as information now being collected is analyzed and treatment regimens are refined, other subtypes of ALL are likely to become therapeutically distinct. The simple morphologic diagnosis of ALL and arbitrary implementation of a standard therapeutic regimen no longer can be considered appropriate care for the child with leukemia. Only by detailed study of each case at diagnosis can these goals be achieved.