Differential Diagnosis for Patient with Low Hgb, Normal MCV, Low Ferritin, and Normal Iron Levels

Single Most Likely Diagnosis

• Anemia of Chronic Disease (ACD): This condition is characterized by low ferritin levels despite normal iron levels, which can occur in the setting of chronic inflammation, infection, or malignancy. The normal MCV and low ferritin levels, along with normal iron levels, make ACD a strong consideration.

Other Likely Diagnoses

• Chronic Kidney Disease (CKD): CKD can lead to anemia due to decreased erythropoietin production. Although the UA is normal, CKD can be present without significant abnormalities on urinalysis, especially in early stages.
• Hypothyroidism: This condition can cause anemia, and while less common, it should be considered, especially if other symptoms suggestive of hypothyroidism are present.
• Chronic Inflammatory Conditions: Conditions like rheumatoid arthritis, lupus, or other autoimmune diseases can lead to anemia of chronic disease, similar to ACD.

Do Not Miss Diagnoses

• Gastric Cancer or Other Malignancies: Although the colonoscopy is normal, other parts of the GI tract or other organs could be involved. Gastric cancer, for example, can lead to iron deficiency anemia due to chronic blood loss, but in early stages, iron levels might still be normal.
• Celiac Disease: This autoimmune disorder can lead to malabsorption of iron and other nutrients, potentially causing anemia. The fact that ferritin is low despite normal iron levels could suggest a problem with iron utilization or absorption.
• Thalassemia Minor: Although typically associated with a low MCV, some forms of thalassemia can present with a normal MCV. It's crucial to consider this diagnosis, especially in individuals of Mediterranean, African, or Asian descent.

Rare Diagnoses

• Porphyrias: A group of disorders that can affect the production of heme, leading to anemia. They are rare and might present with a variety of symptoms, including neurological and cutaneous manifestations.
• Sideroblastic Anemia: A disorder where the bone marrow fails to utilize iron to create hemoglobin, leading to a buildup of iron within mitochondria of red blood cell precursors. It can be congenital or acquired and is relatively rare.
• Pure Red Cell Aplasia: A rare condition where the bone marrow fails to produce red blood cells, leading to severe anemia. It can be primary (idiopathic) or secondary to other conditions, including autoimmune diseases, drugs, or viral infections.