Many factors have been associated with venous thromboembolism. Among them, vitamin B12 deficiency can produce elevated homocysteine levels, which is a risk factor for venous embolism, since the latter interferes with the activation of Va coagulation factor by activation of C protein. We present a case of a patient with metabolic syndrome with apparently unprovoked pulmonary embolism. After careful evaluation, megaloblastic anemia was detected. Even though the patient had biochemistry findings of hemolysis and blood smear did not showed fragmented erythrocytes, which is consistent with pseudo-microangiopathic hemolytic anemia.
Keywords: B12 deficiency; Megaloblastic anemia; Pulmonary embolism.