SummaryThe authors report a case of acute non lymphoblastic leukemia, amoeboid movement configuration variant, which followed an indolent course. Only symptomatic treatment was given, consisting in red cell transfusions.Experimentally different kinds of lymphoid stimulations can induce such a configuration. In clinical observations, cells with an amoeboid movement configuration have been encountered in several hematologic diseases, malignant or not, of lymphoid and non-lymphoid lineages.Several hypotheses relative to the biological significance of such cell configurations are presented. Their prognostic value in cases of acute leukemia is also mentioned.