What is the appropriate diagnosis and treatment for a 17-year-old female with a post-auricular lesion, leukopenia (low White Blood Cell (WBC) count), anemia (low Red Blood Cell (RBC) count, Hemoglobin (H&H) and Mean Corpuscular Volume (MCV))?

Pancytopenia with Post-Auricular Lesion in Adolescent Female

This clinical presentation of pancytopenia (low WBC, RBC, H&H, and MCV) in a 17-year-old female with a post-auricular lesion requires immediate hematologic evaluation with bone marrow biopsy to exclude acute leukemia, aplastic anemia, or other bone marrow failure syndromes, as the combination of cytopenias across all cell lines indicates a serious underlying hematologic disorder rather than simple nutritional deficiency. 1, 2

Critical Diagnostic Considerations

Pancytopenia Workup Priority

The simultaneous reduction of all three cell lines (WBC, RBC, platelets implied by low H&H and MCV) suggests bone marrow failure or infiltrative process rather than isolated anemia. 1, 2 This pattern is fundamentally different from simple iron deficiency anemia, which would not cause leukopenia. 2, 3

Immediate laboratory evaluation must include:

• Complete blood count with manual differential to assess for dysplasia, blasts, or abnormal cells 1, 4
• Peripheral blood smear to evaluate cell morphology and identify schistocytes, blasts, or dysplastic features 1, 4
• Reticulocyte count to distinguish between production failure (low count) versus destruction/loss (elevated count) 1, 2
• Comprehensive metabolic panel including LDH, bilirubin, haptoglobin to assess for hemolysis 1, 2
• Bone marrow aspiration and biopsy with cytogenetics is mandatory given pancytopenia to exclude acute leukemia, myelodysplastic syndrome, aplastic anemia, or marrow infiltration 1

Acute Leukemia Must Be Excluded

The NCCN guidelines for acute myeloid leukemia specify that diagnostic evaluation includes bone marrow with cytogenetics, immunophenotyping, and molecular analyses when pancytopenia is present. 1 Leukopenia with anemia in an adolescent raises concern for acute leukemia or bone marrow failure syndrome, which requires urgent hematology consultation. 1, 4

Post-Auricular Lesion Evaluation

The post-auricular lesion requires separate assessment but may provide diagnostic clues:

• If the lesion is a keloid or benign growth, this is likely unrelated to the hematologic abnormalities and represents a separate cosmetic issue 5, 6
• If the lesion represents lymphadenopathy, this could indicate lymphoma, leukemic infiltration, or infectious process contributing to cytopenias 1
• Physical examination should assess for hepatosplenomegaly, other lymphadenopathy, petechiae, or bruising that would support hematologic malignancy 1

Why This Is NOT Simple Iron Deficiency

While the low MCV might initially suggest iron deficiency, several features argue strongly against this diagnosis:

• Leukopenia does not occur with iron deficiency anemia 2, 3, 7
• Iron deficiency presents with isolated microcytic anemia, not pancytopenia 2, 3
• The combination of low WBC, RBC, and low MCV suggests bone marrow failure with ineffective erythropoiesis rather than nutritional deficiency 1, 8
• While rare cases of leukopenia after IV iron therapy have been reported (1.91% prevalence), this occurs after treatment, not before 7

Immediate Management Algorithm

Step 1: Urgent hematology consultation - Pancytopenia in an adolescent requires specialist evaluation within 24-48 hours 1, 4

Step 2: Complete diagnostic workup as outlined above, with bone marrow biopsy being the definitive diagnostic procedure 1

Step 3: Assess for infection risk - If absolute neutrophil count is severely reduced (<500/μL), the patient requires protective isolation and consideration for prophylactic antibiotics 4

Step 4: Avoid empiric iron supplementation until bone marrow pathology is known, as this can cause harm in conditions like thalassemia or sideroblastic anemia and delays proper diagnosis 3

Step 5: Transfusion support may be needed if hemoglobin <7-8 g/dL with symptoms, but should await hematology guidance 1

Critical Pitfalls to Avoid

• Do not attribute pancytopenia to nutritional deficiency alone without bone marrow evaluation - this can delay diagnosis of life-threatening conditions like acute leukemia 1, 3
• Do not start empiric iron therapy before confirming the diagnosis, as this obscures the diagnostic picture and can be harmful 3
• Do not dismiss leukopenia as incidental - in combination with anemia and low MCV, this represents a serious hematologic disorder requiring urgent investigation 1, 4
• Agranulocytosis with fever is a medical emergency requiring immediate hospitalization and broad-spectrum antibiotics 4