Inversion of chromosome 16 and eosinophilia in refractory anemia with ring sideroblasts: report of a case.

A 72-year-old male who was admitted to our hospital with severe anemia was diagnosed as refractory anemia with ring sideroblasts (RARS), according to the French-American-British (FAB) classification of myelodysplastic syndromes (MDS). The patient showed persistent eosinophilia with no definite signs of either allergy or a parasitic infection. Chromosomal analysis of bone marrow cells revealed inv(16)(p13q22), a known characteristic of M4Eo acute myeloid leukemia (AML) in the FAB classification. This patient didn't exhibit leukemic transformation during his 20-month clinical course, nor was any found at autopsy. Therefore, this is the first case of RARS to speculate that the chromosomal characteristic inv(16)(p13q22) might be specific for eosinophilia rather than AML.