Schistocytes on a blood smear are commonly associated with which condition?

Schistocytes are fragmented red blood cells that can be observed on a peripheral blood smear and are indicative of microangiopathic hemolytic anemia. The presence of schistocytes is most commonly associated with conditions that result in mechanical destruction of red blood cells, such as Disseminated Intravascular Coagulation (DIC).

In DIC, there is an abnormal activation of the coagulation cascade, leading to the formation of small blood clots throughout the microcirculation. As red blood cells pass through these obstructed areas, they become damaged and fragmented, resulting in the formation of schistocytes.

The other conditions listed, such as Vitamin B12 deficiency, iron deficiency anemia, and infectious mononucleosis, do not typically lead to the formation of schistocytes. Instead, they are characterized by different types of hematological abnormalities, such as megaloblastic changes or normocytic/microcytic anemia without fragmentation of red blood cells. Therefore, the association of schistocytes with DIC is particularly strong, making it the correct answer in this context.