Schistocytes
Synonyms: Schistocytes, fragmentocytes, helmet cells
Schistocytes, or fragmentocytes, are ruptured erythrocytes caused by mechanical stress, which can occur from, for example, intravascular coagulation, in which the erythrocytes are cut up by fibrin threads. Other causes may be prosthetic heart valves, extracorporeal circulation or dialysis, or burns.
Schistocytes may also be seen in disorders of the cytoskeleton of the erythrocyte (e.g., pyropoikilocytosis) or when the erythrocytes are relatively fragile due to insufficient nutrients (e.g., iron deficiency)
When both fragmentocytes and a thrombopenia are seen, one should be mindful of the syndrome Thrombotic thrombocytopenic purpura (TTP).
