Polysomy 8 Syndrome: A Distinct Clinical Entity Comprising of Myelomonocytic/Monocytic Lineage Involvement in Acute Leukemia

Purpose: Cytogenetic abnormalities have been proven to be among the most valuable prognostic indicators in leukemia, allowing the stratification of patients in risk groups. We describe a patient diagnosed as AML-M5, with myeloid sarcoma and tetrasomy 8 as the sole chromosomal abnormality. We confirm that the presence of polysomy 8 in myeloid lineage malignancies is associated with a distinct clinical entity comprising of myelomonocytic/monocytic lineage involvement, poor prognosis and high incidence of myeloid sarcoma. In aim to obtain a detailed description of this clinical entity, literature of polysomy 8 cases has been reviewed. Methods: Cytogenetic analysis was performed on bone marrow samples directly after aspiration and following 24 h short term culture. Fluorescence in situ hybridization (FISH) analyses were performed at complete remission stage on interphase nuclei from bone marrow. Results: Cytogenetic analyses revealed tetrasomy 8 as the sole karyotipic change in all metaphases. The presence of tetrasomy was confirmed with C-MYC (8q24), AML1/ETO (ETO-8q21) and chromosome 8 centromeric probe cocktail. Conclusion: Recognition of the polysomy 8 syndrome will allow for the development of a standardized approach to these patients; as well as stimulating further research into the biology of the disorder that will allow for the development of better therapeutic strategies. Keywords: Tetrasomy 8, Acute Myeloid Leukemia, AML-M5, Myeloid Sarcoma, Polysomy 8 Syndrome, Cytogenetics