Dysplastic eosinophils in three patients with acute promyelocytic leukaemia

Three cases of acute promyelocytic leukaemia (M3) with dysplastic eosinophils are reported. Promyelocytes from these cases showed classical features of hypergranular acute promyelocytic leukaemia. All the cases had minimal organomegaly and disturbances of coagulation were minimal. All the cases were associated with dysplastic eosinophils in the marrow but very few of these eosinophils were found in peripheral smear. One of the three patients presented with a mass in the vertebral column, a feature not uncommonly seen in a variant form of AML-M2 with eosinophilia. Dysplastic eosinophils appear to arise from leukaemic clone itself. These three cases probably represent hitherto undescribed morphological variant of acute promyelocytic leukaemia where leukaemic cells show limited differentiation capability to dysplastic eosinophils.