Morphologic characteristics of acute lymphoblastic leukemia (ALL) with abnormalities of chromosome 8, band q24.

The CALGB prospectively studied 140 adult acute lymphoblastic leukemia (ALL) patients for cytogenetic abnormalities. Seven (5%) patients with adequate cytogenetic preparations had t(8;14)(q24;q32) or t(8;22)(q24;q11). Patients were compared with non-8q24 patients for clinical and laboratory characteristics, response to therapy, and survival. The median age of patients with translocations involving 8q24 (71% males) was 40 years. Forty-three percent had lymphadenopathy, 29% splenomegaly, and 29% hepatomegaly. None exhibited central nervous system (CNS), skin, or gum involvement. These features did not differ significantly from non-8q24 ALLs. Patients with 8q24 translocations had higher hemoglobins (11.5 vs. 9.8 g/dl; P = 0.04) and lower percentage of blasts in the peripheral blood (8.5% vs. 69%; P = 0.007). Although all seven were finally categorized as ALL-L3, a marked variation in the proportion of typical L3 blasts was observed that initially resulted in the diagnoses of ALL-L2 in three cases and prolymphocytic leukemia in one. In five of five patients, the blasts typed as B cells (SIg+ and CD19+). Complete remission rates for patients with 8q24 translocations were 43%, whereas they were 68% for non-8q24 ALLS (P = 0.22). Furthermore, patients with 8q24 abnormalities exhibited significantly shorter survival (4.8 vs. 18.4 mo; P less than 0.001). We conclude that ALL with translocations of 8q24 in adults shows a mature B-cell immunophenotype (SIg+), poor prognosis and morphology ranging from classical ALL-L3 to ALL with a subpopulation of L3 cells. Thus, the diagnosis of ALL-L3 should be made when blastic cells possess a mature B-cell immunophenotype (SIg+) and an 8q24 translocation, even though the number of L3 cells is low.