Enlarged and prominent nucleus may be indicative of tetraploidy: a laboratory study of a rare near-tetraploidy in a child patient with acute myelogenous leukemia AML-M4.

SUMMARY: Near-tetraploidy is a rare cytogenetic abnormality in myelocytic malignancies in children and its significance is unknown. To investigate the pathologic characteristics of a near-tetraploidy in a child with acute myelogenous leukemia (AML-M4), bone marrow smears were prepared for morphologic analysis. Bone marrow samples were collected at presentation for flow cytometry, prepared by short-term (24 h) unstimulated culture and R-banding for conventional cytogenetic assay. We have performed a multifactorial analysis of the laboratory test results. In this case, the chromosomal analysis (R-banding) demonstrated a near-tetraploidy. Combined with morphologic and immunophenotypic results, the diagnosis was established as acute myelogenous leukemia (AML-M4). Near-tetraploidy is an uncommon cytogenetic finding, and the experience of this case further emphasizes the importance of the laboratory diagnostic methods.