We herein report a rare case of acute basophilic leukemia with t(16;21)(p11;q22) generating the FUS-ERG fusion gene. The basophilic nature of leukemia blasts was demonstrated by cytomorphology, toluidine blue metachromasia, mature basophil-associated antigen expression, and characteristic granules under electron microscopy. The molecular link between t(16;21)/FUS-ERG and basophilic differentiation remains unclear.
Keywords: Acute basophilic leukemia; electron microscopy; metachromasia; t(16;21)(p11;q22) translocation; the FUS‐ERG fusion gene.