Agressive Acute Myeloid Leukemia with inv(3)(q21q26.2): A Case Report

Acute myeloid leukemia with inv(3)(q21q26.2) is an aggressive and relatively rare subtype of leukemia. Typically, it may present de novo or arise from a prior myelodysplastic syndrome; therefore, multilineage dysplasia can be a common finding. This report describes the case of a 38-year-old woman, who presented a clinical indication of acute leukosis. Blood tests results showed LDH 708 U/L, PCR 230 mg/L, hemoglobin 7.5 g/dL and WBC count of 92.45 x 109/L in peripheral blood (PB), 25% of blasts, 48% of vacuolated monocytes with irregular nuclei, dysplastic granulocytes, and giant hypogranular platelets. The immunophenotyping of PB sample showed the presence of 11.5% of myeloid blasts and 81.4% of cells with characteristics and maturation pattern of monocytic lineage; some of them exhibited phenotypic alteration. Karyotype analysis of the PB sample showed [inv(3)(q21q26)] with a secondary abnormality [t(1;15)(q10;q10)]. Pleural fluid analysis showed LDH 748 U/L and 2.950 cells/mm3 of which 54% had increased size and immaturity features. Due to the aggressiveness of the disease and secondary clinical events, the patient died four days after being hospitalized. This case demonstrated the importance of detailed laboratory tests correlations in achieving differential diagnosis of hematologic malignancies. The initial diagnosis of AML with monocytic differentiation was suspected after analysis of immunophenotyping which presented a large monocytic component. However, the occurrence of inv(3)(q21q26), associated with multilineage dysplasia, pointed to AML with inv(3)(q21q26). The severity of the disease was demonstrated by the presence of malignant cells in pleural fluid, which represents information not frequently reported in other studies.

Keywords: Acute myeloid leukemia; AML with inv(3); cytogenetic analysis.