Moschowitz first described thrombotic thrombocytopenic purpura (TTP) in 1925 in a 16-yearold female who presented with fever, petechiae, and a microangiopathic hemolytic anemia. Autopsy examination at the time revealed hyaline thrombi in the vascular beds of many organs. By 1947, several more cases were described and Singer suggested the term TTP. In 1964, Amorosi and Ultmann published a review of all cases and introduced the “classic pentad” used to diagnose TTP. With recent advances and discoveries, it is now accepted that TTP and hemolytic uremic syndrome (HUS) are distinct diseases (although there is significant overlap) under the larger category of thrombotic microangiopathies, both presenting with a microangiopathic hemolytic anemia (MAHA), with no apparent cause along with renal and/or neurologic manifestations.