A pericentric inversion of chromosome 16 is associated with dysplastic marrow eosinophils in acute myelomonocytic leukemia.

Cytogenetic studies were performed in 18 consecutive children with acute nonlymphocytic leukemia (ANLL) between 1981 and 1983. Three children with acute myelomonocytic leukemia (AMMoL; M4, FAB classification) had the following unique bone marrow morphology and cytogenetic abnormality: eosinophilic precursors with dysplastic violaceous granules and a pericentric inversion of chromosome 16. Surface marker analysis of leukemic cells from these patients, using a panel of monoclonal antibodies, revealed the expression of a series of monocyte markers. The association of an inversion of chromosome 16 with abnormal eosinophil morphology in the M4 subtype of ANLL appears to represent a unique subgroup of patients.