Performance of , , and break-apart FISH in small biopsies with large B-cell lymphoma: a retrospective Cytopathology Hematopathology Interinstitutional Consortium study.

Introduction: Fluorescence hybridization (FISH) is an essential ancillary study used to identify clinically aggressive subsets of large B-cell lymphomas that have , or rearrangements. Small-volume biopsies such as fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB) are increasingly used to diagnose lymphoma and obtain material for ancillary studies such as FISH. However, the performance of FISH in small biopsies has not been thoroughly evaluated or compared to surgical biopsies.

Multilineage involvement in KMT2A-rearranged B acute lymphoblastic leukaemia: cell-of-origin, biology, and clinical implications.

Aims: B lymphoblastic leukaemia/lymphoma (B-ALL) is thought to originate from Pro/Pre-B cells and the genetic aberrations largely reside in lymphoid-committed cells. A recent study demonstrated that a proportion of paediatric B-ALL patients have BCR::ABL1 fusion in myeloid cells, suggesting a chronic myeloid leukaemia (CML)-like biology in this peculiar subset of B-ALL, although it is not entirely clear if the CD19-negative precursor compartment is a source of the myeloid cells. Moreover, the observation has not yet been extended to other fusion-driven B-ALLs.