Recognized causes of schistocytosis:
(1) micro-angiopathic hemolytic anemia: fragmentation in capillaries and small arterioles associated with DIC or TTP/HUS
(2) vasculitis: autoimmune vs infectious
(3) heart valves - prosthetic or with distorted native valves
(4) pregnancy-related: eclampsia, HELLP syndrome
(5) march hemoglobinuria, runner's anemia
(6) severe burns
(7) snakebite
(8) chemical or toxic drug exposure
(9) giant cavernous hemangioma
Differential diagnosis - red cell disorders without trauma to erythrocytes:
(1) unstable hemoglobin - sickle cell anemia, sickle-thalassemia, other hemoglobinopathy
(2) iron deficiency anemia - The poikilocytosis with circulating red cell fragments associated with iron deficiency anemia may be mislabeled as schistocytosis. However, iron deficiency may arise with chronic intravascular hemolytic anemias.
