CEL is a haematological rarity distinguished by the clonal expansion of eosinophilic lineage cells in the peripheral circulation, bone marrow, and various anatomical sites.5 The convergence of Loeffler endocarditis with CEL, particularly when associated with the FIP1L1-PDGFRA rearrangement, poses intricate challenges in both diagnosis and management. This evidence concerns the gene FIP1L1 and Chronic Eosinophilic Leukemia, Not Otherwise Specified.