Certified Pediatric Hematology Oncology Nurse (CPHON) Practice Exam 2025 - Free CPHON Practice Questions and Study Guide

Diamond Blackfan Anemia (DBA) is characterized by an intrinsic failure of the red blood cell production in the bone marrow, leading to a specific form of macrocytic anemia. In this condition, the red blood cells produced are larger than normal due to the ineffective erythropoiesis, which is a hallmark of the disorder. Macrocytic anemia is associated with an increase in mean corpuscular volume (MCV) because the erythrocytes that are produced have not gone through the normal maturation process.

In DBA, the bone marrow is usually hypocellular but has high levels of erythroid precursor cells that are unable to mature properly, which contributes to the presence of macrocytosis. The unique morphology of the red blood cells, along with the low number of overall erythrocytes, points directly to macrocytic anemia as a typical laboratory finding in patients with this condition.

This understanding clarifies why macrocytic anemia is the correct answer, as it aligns with the pathophysiology and clinical presentation of Diamond Blackfan Anemia.