A B-ALL Pediatric Patient with a Cryptic IGH Rearrangement Within the Context of a Complex Karyotype

Area of Science:

• Hematology
• Oncology
• Genetics

Background:

• B-cell acute lymphoblastic leukemia (B-ALL) is a heterogeneous malignancy affecting both pediatric and adult populations.
• Characterized by the accumulation of immature B lymphoblasts, B-ALL necessitates precise diagnostic and prognostic evaluations.
• Immunophenotypic and cytogenetic analyses are crucial for understanding disease biology and guiding treatment strategies.

Purpose of the Study:

• To present a rare case of B-cell acute lymphoblastic leukemia (B-ALL) in a young adult male.
• To detail the complex genetic landscape, including immunoglobulin heavy chain (IGH) gene rearrangements, observed in this patient.
• To highlight the diagnostic and therapeutic implications of rare genetic abnormalities in B-ALL.

Main Methods:

• Bone marrow aspiration and analysis for B lymphoblasts and pancytopenia.
• Immunophenotyping using flow cytometry to identify cell surface markers (CD19, CD10, CD34, etc.).
• Cytogenetic analysis including complex karyotyping and fluorescence in situ hybridization (FISH) for IGH and MYC gene rearrangements.

Main Results:

• The patient presented with acute pre-B lymphoblastic leukemia, with 90% bone marrow infiltration by B lymphoblasts.
• Immunophenotyping revealed predominant immature precursor B lymphoid cells.
• Complex karyotype and significant IGH gene rearrangement (96.5%) were identified, with a gain of IGH signal also noted.
• FISH analysis refined the karyotype, identifying an add(8)(p11.2) with an IGH signal.

Conclusions:

• IGH gene abnormalities, though rare in B-ALL, can occur and are often linked to poorer prognoses.
• This case demonstrates a complex genetic profile in B-ALL with IGH rearrangement.
• Despite the rare genetic findings, the patient achieved a complete cytogenetic response to therapy, indicating potential for successful treatment even in complex cases.