Snapshot A 35-year-old man presents to the clinic for follow-up for treatment of latent tuberculosis. He is a recent immigrant to the United States from Mexico and started taking isoniazid 2 months ago after he was diagnosed with latent tuberculosis at an occupational health visit. Physical examination is notable for decreased sensation to pinprick in his lower extremities. A bone marrow aspirate is obtained and after staining with Prussian blue, the finding in the image is observed. Introduction Overview login to view 2 more bullets Epidemiology login to view 10 more bullets Pathophysiology login to view 16 more bullets Genetics login to view 5 more bullets Prognosis login to view 3 more bullets Presentation Symptoms login to view 6 more bullets Physical exam login to view 6 more bullets Studies Serum labs login to view 3 more bullets Histology login to view 8 more bullets Differential Iron deficiency anemia login to view 2 more bullets Megaloblastic anemia login to view 2 more bullets Treatment Medical pyridoxine (vitamin B6) supplementation