Precursor Lymphoid Neoplasms

Precursor lymphoid neoplasm consists mainly of B-lymphoblastic leukemia/lymphoma (B-ALL) and T-lymphoblastic leukemia/lymphoma (T-ALL). They are malignant disorders of immature B or T-cells that occur typically in children. Approximately 75% of the patients are under the age of 6. To diagnose the diseases, karyotyping, FISH, PCR, or next-generation sequencing (NGS) is used to identify chromosome abnormalities including rearrangements of BCR::ABL1, KMT2A, ETV6::RUNX1, TCF3::PBX1, IGH::IL, TCF::HLF, hyperdiploidy, hypodiploidy, iAML21, T-cell receptor gene rearrangement, etc. Gene mutations associated with ALL are generally identified by NGS. The information from these tests will provide patients with targeted therapy, predictive prognosis, and risk stratification. In this chapter, a few cases are used to illustrate how these tests will benefit patients including a large pediatric population.