[Unexpected death by leukostasis and lung leukostatic tumors in acute myeloid leukemia. Study of four cases].

Four cases of unexpected death due to acute myeloid leukemia have been studied: myeloblastic M1 (case I and II), promyelocytic M3 (case III), myelomonocytic M4 (case IV). Diagnosis was performed before death only in case III. Histological leukostasis was the most evident feature in all cases, particularly at the lung level, where tumor-like aspects were evident and widely diffused in case II. The last three cases were pregnant at the third trimester. Serious hemorrhagic complications were evident in all cases: CID in the former 3 cases and primary hyperfibrinolysis in the 4th, as demonstrated by the absence of intravascular cloths in many organs and especially in lung and kidney; abundant, on the contrary, in the former three cases. Leukostasis was not associated to hyper-leucocytosis in all 4 cases, but associated to normal number of peripheral white cells (below normal level in case III). This phenomenon, that disagrees with literature data on acute or chronic reactivated myeloid leukemia leukostasis, may be due to the primary confination of the immature granuloblasts in the vascular bed, because of the hemoreologic effects connected with their deficient plasticity, that is essential for normal granulocytes to flow easily in the capillary bed. In all cases death was caused by breathing and cardiocirculatory insufficiency with the associated unceasing hemorrhages.