Assessment of Laboratory Values in an 11-Year-Old Male
These laboratory values are completely normal and require no intervention.
The reported values (WBC 10.7 × 10⁹/L, lymphocytes 4.5 × 10⁹/L, eosinophils 0.5 × 10⁹/L) all fall within normal pediatric reference ranges for an 11-year-old child. In an otherwise healthy patient with normal total WBC count, no fever, and no clinical symptoms, observation without additional testing is the appropriate approach 1.
Normal Pediatric Reference Ranges
- Total WBC count: Normal range for children aged 6-18 years is approximately 4.5-13.5 × 10⁹/L 2
- Absolute lymphocyte count: 1.5-6.5 × 10⁹/L is typical for this age group 2
- Eosinophil count: 0.0-0.7 × 10⁹/L is within normal limits 2
The patient's WBC of 10.7 × 10⁹/L is well below the threshold of 14,000 cells/mm³ that would suggest bacterial infection (likelihood ratio only 3.7) 1.
Clinical Context Required
Assessing for any clinical symptoms including fever, night sweats, weight loss, fatigue, splenomegaly, lymphadenopathy, or signs of focal infection is crucial 1. In the absence of these findings:
- No additional diagnostic workup is warranted 1
- No imaging studies are indicated 2
- No hematologic consultation is needed 2
When to Pursue Further Evaluation
Further investigation would only be appropriate if any of the following were present:
- Fever or systemic symptoms suggesting infection or malignancy 1, 2
- Persistent elevation of WBC count on repeat testing in 4-6 weeks 1
- Left shift with ≥16% band neutrophils or ≥1,500 absolute band count (likelihood ratio 4.7-14.5 for bacterial infection) 1
- Abnormal cell morphology on peripheral smear showing blasts, immature cells, or dysplasia 3
- Concurrent cytopenias or other blood count abnormalities 4
Critical Pitfalls to Avoid
- Do not pursue extensive workup for normal laboratory values in asymptomatic patients 1
- Do not assume any elevation requires investigation - these values are not elevated 2
- Do not rely on automated differential alone if there were concerns; manual differential with peripheral smear examination would be preferred for accurate assessment 1