What is the significance of a hemoglobin of 12.1 g/dL, mean corpuscular volume 81 fL, mean corpuscular hemoglobin 26 pg, red‑cell distribution width 15.2 %, and platelet count of 115 ×10³/µL in an otherwise healthy adult?

Laboratory Values Interpretation

Your laboratory results show mild microcytic anemia with borderline thrombocytopenia and elevated red cell distribution width, which together suggest iron deficiency anemia as the most likely diagnosis, though the thrombocytopenia requires separate evaluation to exclude bone marrow dysfunction or other pathology. 1

Individual Parameter Analysis

Hemoglobin: 12.1 g/dL

• Mild anemia by WHO criteria (normal: ≥12 g/dL for women, ≥13 g/dL for men) 2
• If you are female, this represents borderline anemia; if male, this is clearly anemic 2
• This level typically does not cause severe symptoms but may contribute to fatigue, exercise dyspnea, or headache 2

Mean Corpuscular Volume (MCV): 81 fL

• Low-normal to mildly microcytic (normal range: 80-100 fL) 2
• MCV <80 fL classically indicates microcytic anemia, most commonly from iron deficiency, thalassemia, anemia of chronic disease, or sideroblastic anemia 2
• Your value of 81 fL sits just at the threshold, suggesting early or mild microcytic process 2

Mean Corpuscular Hemoglobin (MCH): 26 pg

• Low (normal range: approximately 27-33 pg)
• Indicates hypochromic red blood cells with reduced hemoglobin content 2
• This pattern (low MCV + low MCH) strongly supports iron deficiency anemia 2, 1

Red Cell Distribution Width (RDW): 15.2%

• Elevated (normal range: 11.5-14.5%)
• Indicates increased variability in red blood cell size (anisocytosis) 3, 4
• Elevated RDW with low-normal MCV is characteristic of iron deficiency anemia, where both small and normal-sized cells coexist 5
• RDW elevation can also indicate mixed nutritional deficiencies or early stages of anemia 3

Platelet Count: 115 × 10³/µL (assuming you meant 115, not 11.5)

• Mild thrombocytopenia (normal range: 150-400 × 10³/µL) 2
• This level is generally safe for most activities and does not require platelet transfusion 2
• Platelet counts >50 × 10³/µL are adequate for most procedures, and >100 × 10³/µL for major surgery or ongoing bleeding 2
• Critical point: Iron deficiency alone does NOT cause thrombocytopenia—this finding requires separate investigation 1

Clinical Significance: Red Flag for Multi-Lineage Cytopenia

The combination of anemia AND thrombocytopenia represents abnormalities in two cell lines and mandates hematology consultation, as this raises concern for bone marrow dysfunction beyond simple nutritional deficiency. 1

• Do not presume iron deficiency alone explains both cytopenias without excluding more serious pathology such as myelodysplastic syndrome, aplastic anemia, or bone marrow infiltration 1, 6
• Abnormalities in two or more cell lines should be evaluated carefully and likely warrant discussion with a hematologist 1

Recommended Diagnostic Workup

Immediate Testing Required:

• Serum ferritin and transferrin saturation to confirm iron deficiency (ferritin <30 μg/L confirms iron deficiency in absence of inflammation; transferrin saturation <15-20% supports diagnosis) 2, 1
• Complete blood count with differential to assess white blood cell count and all cell lines 1, 6
• Peripheral blood smear to evaluate cell morphology and identify any dysplastic features or abnormal cells 1, 6
• Reticulocyte count to assess bone marrow response (low count suggests impaired production) 2, 1
• Inflammatory markers (CRP, ESR) as inflammation affects ferritin interpretation 2, 6

Additional Testing if Initial Workup Unclear:

• Vitamin B12 and folate levels to exclude combined deficiency 1
• Comprehensive metabolic panel to assess renal function, as renal disease can cause anemia 6
• LDH and haptoglobin if hemolysis suspected 6

When to Pursue Bone Marrow Evaluation:

• Persistent unexplained thrombocytopenia after iron deficiency treatment 6
• Any additional cytopenias (leukopenia) 6
• Abnormal cells on peripheral smear 6
• Failure to respond to appropriate iron supplementation 1

Common Pitfalls to Avoid

• Do not accept ferritin alone in patients with inflammation; use transferrin saturation to confirm iron deficiency 1
• Do not rely on MCV alone, as iron deficiency can present with normal MCV in early stages 1
• Do not overlook the thrombocytopenia—this is not explained by iron deficiency alone and requires separate evaluation 1
• Do not assume dietary insufficiency as the sole cause without confirming with iron studies and excluding other pathology 1
• Do not delay hematology referral if multi-lineage cytopenia persists or worsens 6