Anemia Workup: Is This Anemia Related to an Underlying Condition?
Based on your laboratory values, this patient does NOT have iron deficiency anemia—the MCV is normal (96.7 fL) and the iron studies do not support iron deficiency, so you must look for other causes of anemia unrelated to iron deficiency. 1
Laboratory Analysis
Your patient's labs reveal:
- Hemoglobin 10.4 g/dL (anemic) 2
- MCV 96.7 fL (normocytic, NOT microcytic) 2
- Total iron 55 mcg/dL (low-normal to low)
- TIBC 255 mcg/dL (normal to low-normal)
- Transferrin saturation approximately 22% (calculated: 55/255 × 100)
This pattern is NOT consistent with iron deficiency anemia. True iron deficiency would show:
- Microcytosis (MCV <80 fL) 2
- Elevated TIBC (typically >360 mcg/dL) 1
- Low transferrin saturation (typically <20%) 1
- Low ferritin (ideally <45 ng/mL) 2, 1
Critical Missing Information
You have not provided the serum ferritin level, which is the most powerful test for iron deficiency. 2, 1 Without ferritin, definitive classification is impossible, but the normal MCV strongly argues against iron deficiency. 2
What This Anemia Pattern Suggests
The normocytic anemia with relatively low-normal iron studies and normal-to-low TIBC suggests:
- Anemia of chronic disease/inflammation (most likely given the pattern) 2
- Combined deficiency states (e.g., concurrent B12 or folate deficiency masking microcytosis) 2
- Chronic kidney disease 1
- Hemolysis or bone marrow disorders
- Early iron deficiency (though the normal MCV makes this less likely) 2
The negative stool guaiac does NOT rule out gastrointestinal pathology, as fecal occult blood testing is of no benefit in investigating anemia. 2, 1
Recommended Next Steps
Immediate Laboratory Testing Needed:
- Serum ferritin (essential for diagnosis) 2, 1
- Reticulocyte count (assess bone marrow response)
- Peripheral blood smear (evaluate red cell morphology)
- Vitamin B12 and folate levels (rule out combined deficiency) 2
- Inflammatory markers (CRP, ESR) if chronic disease suspected 1
- Creatinine/eGFR (assess for chronic kidney disease) 1
If Ferritin Confirms Iron Deficiency (<45 ng/mL):
Despite the atypical presentation with normal MCV, proceed with gastrointestinal evaluation:
For men and postmenopausal women:
- Bidirectional endoscopy (EGD and colonoscopy) is strongly recommended to exclude GI malignancy 2, 1
- Screen for celiac disease (tissue transglutaminase antibody) 2, 1
- Test for H. pylori (non-invasive testing) 2, 1
For premenopausal women:
- Screen for celiac disease (all patients) 2, 1
- Consider bidirectional endoscopy based on age, severity of anemia, and risk factors 2, 1
- Younger women at low risk may reasonably start with iron supplementation alone 2
If Ferritin is Normal or Elevated:
This is NOT iron deficiency anemia. Focus investigation on:
- The underlying condition mentioned in your question (which you did not specify)
- Chronic inflammatory states 1
- Renal disease 1
- Bone marrow disorders
- Hemolysis
Common Pitfalls to Avoid
- Do not assume microcytosis is always present in iron deficiency—it may be absent in combined deficiencies, but a normal MCV makes pure iron deficiency unlikely 2
- Do not rely on stool guaiac testing—it has no role in anemia workup 2, 1
- Do not assume normal iron studies rule out iron deficiency in inflammatory states—ferritin can be falsely elevated as an acute phase reactant 2, 1
- Do not skip celiac disease screening—it's a common cause of iron malabsorption even without GI symptoms 2, 1
Treatment Considerations
Iron supplementation should only be initiated if iron deficiency is confirmed by ferritin <45 ng/mL. 2, 1 Treating with iron when the underlying cause is chronic disease or another etiology will not correct the anemia and may cause unnecessary side effects. 3, 4
The relationship between this anemia and the patient's underlying condition cannot be determined without knowing what that condition is and obtaining a complete iron panel including ferritin.