unexplained weight loss and asthenia. His immunosuppressive regimen was associated with low-dose corticosteroid, tacrolimus, and mycophenolate mofetil. Complete blood count revealed a low platelet count of 110 × 10 9 /L and a hemoglobin level of 6 g/dl associated with an elevated mean corpuscular volume of 105 fl, but low reticulocyte counts of 36 × 10 9 /L. Thrombotic microangiopathy (TMA) was suspected because of increased lactate dehydrogenase levels (1250 IU/L) and undetectable haptoglobin associated with schistocytes (2%), suggestive of Intravascular hemolysis. F I G U R E 1 Light microscopy of peripheral blood smear in a patient with severe B12 deficiency. (A) Red blood cell fragments (red arrowhead) together with enlarged red blood cells with an oval shape (oval macrocytosis, black arrowhead) and (B) hypersegmented polymorphonuclear, suggestive of B12 deficiency This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.