A case of megaloblastic anemia simulating a cold autoimmune hemolytic anemia.

We report a case of pernicious anemia in which the first diagnosis suspicion was cold autoimmune hemolytic anemia (cAIHA) due to the presence of cold autoantibodies. A 47-year-old woman with a medical history of autoimmune thyroid disease came to the hospital with a clinical and serologic presentation of AIHA. However, because of determination of vitamin B12 (VB12) deficiency, she was finally diagnosed with megaloblastic anemia. In the acute period, the patient received short-term corticosteroid therapy and later VB12. The patient's hemoglobin level and general condition showed improvement.