#00065024

A 64-year-old man was diagnosed with acute myeloid leukemia (AML) in March 2024.The chromosomal analysis of bone marrow sample revealed a visibly balanced reciprocal translocation between the long arms of chromosomes 1 and 11.The matched-metaphase fluorescence in situ hybridization (FISH) analysis confirmed the presence of KMT2A gene rearrangement due to t(1;11).The t(1;11)(q21;q23) results in a KMT2A/MLLT11 fusion and is consistent with AML with KMT2A(MLL) gene rearrangement, according to 5^th edition of the WHO classification of hematolymphoid tumours: Myeloid and histiocytic/dendritic neoplasms. As per the latest european leukemianet (ELN), 2022 guidelines in AML, KMT2A(MLL) gene rearrangement is an 'adverse'-risk cytogenetic abnormality and has a poor impact on outcome. This case highlights the importance of conventional karyotyping in the diagnosis of AML. Additionally, the approach of karyotype-directed FISH analysis is a cost-effective way of prognostication in AML, especially in a resource-limited setting.

Legends for FISH:

A: Peripheral smear showing doughnut neutrophil; B Peripheral smear showing a large blast with a high nuclear-to-cytoplasmic ratio, fine chromatin, prominent nucleoli and scant, basophilic cytoplasm, appearing "empty" due to minimal granulation; C & D: Bone marrow aspirate showing myeloid blasts with large nuclei, fine chromatin, multiple prominent nucleoli and ample basophilic cytoplasm and dysplastic erythroid precursors; E & F: bone marrow biopsy (H&E stained) showing hypercellular marrow with a preponderance of leukemic blasts disrupting marrow architecture.