Constitutional pericentric inversion of chromosome 16, inv(16)(p13.1q22), mimicking acute myeloid leukemia

[...]a multiplex reverse transcriptase-polymerase chain reaction assay covering 28 leukemia-specific fusion transcripts including CBFB::MYH11 was performed by using the HemaVision-28Q kit (VERITAS, Tokyo, Japan), but none of them was detected. [...]it was suggested that the chromosome inversion of this patient did not disrupt the CBFB gene. High-resolution chromosome analysis of the phytohemagglutinin (PHA)-stimulated peripheral blood lymphocytes also revealed inv(16)(p13.1q22) in all 20 cells, indicating a constitutional abnormality of chromosome 16 (Figure 1C). [...]this patient was not misdiagnosed as AML M4Eo and has been followed up without treatment. In these reports, there was no misdiagnosis of AML M4Eo in individuals without hematological malignancy, and in the case of chronic myeloid leukemia with t(9;22)(q34;q11) and inv(16)(p13q22), FISH analysis showed no abnormality of the MYH11 gene and inv(16)(p13q22) was also found in her healthy father, which avoided misdiagnosis as an additional cytogenetic abnormality in chronic phase [ 4]. [...]although extremely rare, we should be aware of the presence of constitutional chromosome abnormalities mimicking hematological malignancies, and it is important to perform further tests such as FISH and genomic analysis for differential diagnosis.