Hyperdiploidy and E2A-PBX1 fusion in an adult with t(1;19)+ acute lymphoblastic leukemia: Case report and review of the literature

✍ Scribed by Stephen P. Hunger; Tsieh Sun; Analea F. Boswell; Andrew J. Carroll; Loris McGavran

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 133 KB
• Volume: 20
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/(sici)1098-2264(199712)20:4<392::aid-gcc11>3.0.co;2-p

✦ Synopsis

The t(1;19)(q23;p13), detected cytogenetically in 5-6% of cases, is one of the most common translocations in childhood acute lymphoblastic leukemia (ALL). Most t(1;19)ϩ ALLs are pseudodiploid or contain fewer than 50 chromosomes, are classified as pre-B based on expression of cytoplasmic, but not surface, immunoglobulin (clg ϩ /slg Ϫ ), express a characteristic pattern of cell surface antigens, and contain E2A-PBX1 fusion mRNAs. A minority of cases are early pre-B (clg Ϫ /slg Ϫ ), do not express the characteristic pattern of cell surface antigens, and lack E2A-PBX1 fusion mRNAs. These latter cases are frequently hyperdiploid, with a modal chromosome number of 55-57. The incidence of the t(1;19) in adults with ALL (ϳ3%) appears to be similar to that observed in children, but the genetic and immunophenotypic features of adult t(1;19)ϩ ALL have not been described extensively. We report a case of t(1;19)ϩ ALL occurring in a 38-year-old man in the setting of hyperdiploidy Ͼ50. Despite this feature, this case was pre-B, conformed to the classic t(1;19) immunophenotype, and expressed E2A-PBX1 fusion mRNAs. This prompted us to review the published literature on ploidy and genetic features of t(1;19)ϩ ALLs. Overall, E2A-PBX1 fusion occurred in 95% (102/107) of t(1;19)ϩ B-lineage ALLs with 50 or fewer chromosomes, 80% of which were pseudodiploid, vs. only 25% (2/8) of t(1;19)ϩ ALLs with more than 50 chromosomes.