A Rare Case of Hemolysis Secondary to Severe Vitamin B12 Deficiency.

An 80 year old female with a past medical history of hypertension, hyperlipidemia, hypothyroidism, and chronic back pain presented to the hospital with fatigue and was found to have a severe macrocytic anemia. Blood work showed pancytopenia and positive markers of hemolysis. Additional work up was consistent with severe vitamin B12 deficiency and pernicious anemia. Her blood counts improved with blood transfusions and vitamin B12 repletion. We discuss the proposed pathophysiology of this rare case of pernicious anemia presenting with hemolysis.