A 55-year-old man comes to the office due to several months of progressive fatigue. He does not have chest pain or shortness of breath. Medical history is significant for hypertension and obesity. BMI is 45 kg/m2. Examination shows mild mucosal pallor. Laboratory results are as follows:
Complete blood count Hemoglobin8.6 g/dL Mean corpuscular volume84 µm3 Reticulocytes0.2% Platelets200,000/mm3 Leukocytes7,500/mm3Serum chemistry Blood urea nitrogen14 mg/dL Creatinine0.8 mg/dL
Which of the following is the most likely cause of this patient's anemia?
A.Anemia of chronic inflammation
B.Extravascular hemolysis
C.Microangiopathic hemolytic anemia
D.Occult blood loss
E.Vitamin B12 deficiency