Case report of Acute Myeloblastic Leukemia with blast count less than 20% in bone marrow

Introduction: Acute Myleloblastic Leukemia is a precursor hamatopoietic malignancy which is seen in any age group and is diagnozed initially as detection of 20% myeloblast in PB or BMA. Based on 2016 WHO classification of hematolymphoid malignancies, some AML with recurrent cytogenetic abnormalities is dropped in one subgroup of AML.The categories of AML with t(8,21), inv(16), t(16,16), or t(15,17) are considered as acute leukemia without regard to blast cell count. Discussion: Patient is a 14 year old boy presenting with fever and petechiae in upper and lower limbs 4-5 days ago , lab data reveals severe leukocytosis, anemia and moderate thrombocytopenia. Imaging data shows only mild splenomegaly. Bone marrow sampling shows severe left shifted myeloid hyperplasia and about 5-6 percent blast, in multicolor flowcytometry about 3 percent blast is isolated. Inspite of oncologist persistence on leukemia according to patient clinical and lab data, diagnosis cannot be confirmed due to low blast count, pathologist is waiting for cytogenetic tests results for AML associated cytogenetic abnormality, surprisingly translocation(8,21) is detected in marrow aspirate and so final diagnosis of Acute Myeloblastic Leukemia is done because the category of AML with above cytogenetic abnormality is considered as AML without regard to blast cell count. Conclusion:In cases suspicious for acute leukemia with low blast count, cytogenetic tests should be performed because the presence of some recurrent cytogenetic abnormalities inspite of blast cell count is considered as AML.

Keywords:

Acute Myeloblatic Leukemia , Recurrent cytogenetic abnormality , low blast count