Pericentric inversion of chromosome 16 and eosinophilia in chronic myelomonocytic leukemia

We report a case of myelodysplastic syndrome with bone marrow eosinophilia and the chromosomal abnormality, inv(16)(p13q22). Hematologic findings including monocytosis and trilineage myelodysplasia were consistent with chronic myelomonocytic leukemia, and numerous abnormal eosinophils were present in the bone marrow. Chromosomal analysis of all metaphase cells from peripheral blood and bone marrow revealed inv(16)(p13q22), which is well known characteristic of acute myelomonocytic leukemia with eosinophilia (M4Eo). Both monocytes and eosinophils in this case may be derived from common leukemic progenitors affected by inv(16)(p13q22).