Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 4 1 2019 07 16 1 4 EN Pardis Nematollahi Department of Hematopathology, Shiraz University of Medical Sciences, Shiraz, Iran, Department of Pathology, School of Medicine, Cancer Prevention Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Behnaz Sabaghi Department of Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Alireza Moafi Department of Pediatric Hematology and Oncology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 2018 08 07 2018 12 23 One of the diagnostic criteria for Acute Myeloblastic Leukemia (AML) is the presence of 20% myeloid blasts in peripheral blood or bone marrow. Some cases with recurrent cytogenetic abnormalities also fall in this category with blast cell count less than 20%. Thus, in the presence of these genetic abnormalities, the patients are classified as AML regardless of blast cell count. One of these genetic heterogeneities is t(8; 21) (q22, q22.1) which is more commonly seen in children and young adults. In this study, a 14-year-old boy is reported with a final diagnosis of AML, which was presented with fever and bicytopenia, clinically suspicious for acute leukemia. Laboratory results reported less than 20% blasts in bone marrow aspiration smears but genetic alteration t(8; 21) (q22, q22.1) was detected by molecular exams. https://crcp.tums.ac.ir/index.php/crcp/article/view/210 https://crcp.tums.ac.ir/index.php/crcp/article/download/210/287