Why Pencil cells are seen in Iron deficiency anaemia?

In iron deficiency anemia, the bone marrow produces abnormally shaped red blood cells, including pencil cells. Pencil cells are elongated, thin, and have pointed ends, resembling the shape of a pencil. These abnormal red blood cells occur due to insufficient hemoglobin synthesis caused by iron deficiency. Hemoglobin, which gives red blood cells their characteristic red color and oxygen-carrying capacity, requires iron for its production. Without adequate iron, hemoglobin synthesis is impaired, leading to the formation of abnormally shaped red blood cells like pencil cells. The presence of pencil cells in a blood sample is a hallmark of iron deficiency anemia and aids in diagnosing the condition.