T-ALL with TEL/AML1 Translocation, Aberrant Expression of CD19 and 33: Case Report and Literature Review

We herewith introduce a 9-year-old boy presenting with leukocytosis, anemia and high lymphoblast count who had a pale complexion as well as weight loss. His cytogenetic analysis revealed aberrant chromosomal rearrangements in different clonal populations harboring 46XY karyotype with t (12; 21) (p12; q22), which was confirmed by DNA sequencing. Flowcytometry assay detected aberrant B lymphocyte and myeloid CD markers such as CD19 (22.0%) and CD33 (20.5%), respectively. To our knowledge, this is the first case of a patient initially diagnosed as TEL/AML1 transcript positive T-ALL expressing CD19 and CD33 markers. The present article also highlights the need for molecular gene rearrangement studies to determine the precise lineage of ambiguous ALL clones.</p