Differential Diagnosis for 80y Female Patient with Weakness and Fatigue

Single Most Likely Diagnosis

• Anemia of Chronic Disease (ACD): Given the patient's age and symptoms of weakness and fatigue, along with laboratory results showing low iron levels (36) but high ferritin (206), this suggests anemia of chronic disease. The low iron saturation (13.8%) and high ferritin are characteristic of ACD, where there is an inflammatory process leading to increased ferritin and decreased iron availability for erythropoiesis.

Other Likely Diagnoses

• Iron Deficiency Anemia (IDA): Although the ferritin is elevated, which might suggest sufficient iron stores, the low iron level and low saturation percentage could also indicate a component of iron deficiency, especially if there's a chronic blood loss or inadequate dietary intake.
• Chronic Kidney Disease (CKD): CKD can lead to anemia due to decreased erythropoietin production. The patient's age and symptoms could be consistent with CKD, especially if there are other signs of renal impairment.

Do Not Miss Diagnoses

• Hemochromatosis: Although less likely given the patient's age and the presentation, hemochromatosis could lead to elevated ferritin and iron levels. However, the low saturation percentage in this case makes it less likely. It's crucial to consider genetic hemochromatosis, especially if there's a family history.
• Malignancy: Certain malignancies can cause anemia of chronic disease or iron deficiency anemia through chronic blood loss or inflammation. Given the patient's age, it's essential to rule out underlying malignancies.
• Thyroid Disease: Both hypothyroidism and hyperthyroidism can cause fatigue and weakness. Although not directly related to the iron studies, thyroid function tests should be considered in the differential diagnosis of fatigue and weakness.

Rare Diagnoses

• Porphyria Cutanea Tarda: A disorder of porphyrin metabolism that can lead to elevated iron levels and ferritin. It's rare and typically presents with skin manifestations, but it could be considered if other diagnoses are ruled out.
• Atransferrinemia: A rare genetic disorder characterized by very low or absent transferrin levels, leading to elevated iron levels but low saturation due to the lack of transferrin to bind iron. The patient's high transferrin level makes this diagnosis unlikely, but it's mentioned for completeness.