As is seen in this patient, the sphenoid sinus may extend beyond the body of the sphenoid bone to pneumatize or involve the adjacent regions. In this case, a lateral recess has been formed within the greater wing of the sphenoid sinus.
1 In general, there are three major types of anemia, classified according to the size of the red blood cells:  If the red blood cells are smaller than normal, this is called microcytic anemia. The major causes of this type are iron deficiency (low level iron) anemia and thalassemia (inherited disorders of hemoglobin).
Anemia caused by low iron - children. Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types of anemia. Iron helps make red blood cells, so a lack of iron in the body may lead to anemia.