Correlation of the FAB morphologic criteria and prognosis in acute lymphocytic leukemia of childhood.

The bone marrows at the time of initial diagnosis of 101 children with acute lymphocytic leukemia diagnosed from April 1969 to December 1974 were evaluated employing the FAB morphologic classification. The group with L1 morphology and a significantly improved duration of first remission and survival when compared to the L2--L3 morphologic groups. Both groups were similar in age and initial level of WBC, indicating that the morphologic classification has prognostic significance in childhood ALL when age and initial WBC were considered together as prognostic risk factors. The L1 morphologic groups survival for the low- and moderate-risk groups was significantly better than for the L1 high-risk group and for the L2--L3 groups.