Differential Diagnosis for Low MCV, MCH, and MCHC on CBC
Single Most Likely Diagnosis
- Iron Deficiency Anemia: This is the most common cause of low MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin), and MCHC (mean corpuscular hemoglobin concentration) values. Iron deficiency leads to a decrease in hemoglobin production, resulting in smaller (microcytic), paler (hypochromic) red blood cells.
Other Likely Diagnoses
- Thalassemia: A genetic disorder affecting hemoglobin production, leading to microcytic, hypochromic anemia. It's more common in certain ethnic groups and can present with varying severity.
- Anemia of Chronic Disease: Chronic diseases like chronic kidney disease, rheumatoid arthritis, or cancer can lead to anemia with low MCV, MCH, and MCHC due to inflammation and impaired iron utilization.
- Sideroblastic Anemia: A disorder where the bone marrow fails to utilize iron to produce hemoglobin, resulting in microcytic, hypochromic anemia.
Do Not Miss Diagnoses
- Lead Poisoning: Although less common, lead poisoning can cause microcytic, hypochromic anemia due to its effect on heme synthesis. It's crucial to consider, especially in children or individuals with occupational exposure.
- Copper Deficiency: Similar to iron, copper is essential for hemoglobin synthesis. Its deficiency can lead to microcytic anemia, though it's rare.
Rare Diagnoses
- Chronic Hemolysis: Conditions like hereditary spherocytosis or autoimmune hemolytic anemia can lead to anemia, but they typically present with normocytic or macrocytic indices rather than microcytic, hypochromic anemia.
- Rare Genetic Disorders: Such as congenital sideroblastic anemia or other inherited disorders affecting hemoglobin synthesis or red blood cell production. These are uncommon and often present with additional clinical features.