Pseudo-Thrombotic Thrombocytopenic Purpura due to Severe Vitamin B12 Deficiency.

As a subset of microangiopathic hemolytic anemia, thrombotic thrombocytopenic purpura can present with a constellation of symptoms similar to the hemolytic anemia attributed to severe vitamin B12 deficiency. There have been few case reports in the medical literature concerning the development of a clinical syndrome consistent with microangiopathic hemolytic anemia attributable to B12 deficiency. We report a case of B12 deficiency leading to microangiopathic hemolytic anemia that was corrected solely with a ten-day course of intramuscular cobalamin replacement. Prompt diagnostic and clinical evaluation utilizing specific exclusion parameters can promote accurate and safe treatment of the clinical syndrome of microangiopathic hemolytic anemia related to B12 deficiency.