Hematology Oncology · Year 2 · from Hematology Oncology
Case 2: Reactive Leukocytosis with Left Shift
Patient Presentation
Demographics: 45-year-old male
Chief Complaint: Fever, productive cough, and shortness of breath for 4 days
History of Present Illness: The patient developed an upper respiratory infection one week ago with rhinorrhea and sore throat. Four days ago, he developed high fevers to 39.5C, productive cough with yellowish-green sputum, and progressive dyspnea. He has right-sided pleuritic chest pain. He denies any chronic medical conditions and takes no regular medications.
Physical Examination:
- Vital signs: BP 105/65, HR 108, RR 24, Temp 39.2C, SpO2 91% on room air
- General: Ill-appearing, diaphoretic
- HEENT: No lymphadenopathy
- Lungs: Decreased breath sounds and crackles at right base with dullness to percussion
- Cardiac: Tachycardic, regular rhythm
- Abdomen: Soft, non-tender, no organomegaly
Workup and Results
Complete Blood Count:
- WBC: 22,400/uL with differential:
- Neutrophils: 78%
- Bands: 15%
- Lymphocytes: 5%
- Monocytes: 2%
- Hemoglobin: 14.2 g/dL
- Platelets: 342,000/uL
Peripheral Blood Smear:
- Neutrophilia with left shift (increased bands)
- Toxic granulation in neutrophils
- Dohle bodies present
- No blasts or abnormal cells
Chest X-ray:
- Right lower lobe consolidation with air bronchograms
- Small right pleural effusion
Sputum Culture:
- Gram stain: Many PMNs, gram-positive diplococci
- Culture pending
Clinical Image
Peripheral blood smear showing neutrophil with toxic granulation (dark coarse granules) indicating reactive response to infection. Image source: Wikimedia Commons. License: CC BY-SA 4.0
Diagnosis
Community-Acquired Pneumonia with Reactive Leukocytosis
Features of reactive (vs. malignant) leukocytosis:
- Clear infectious trigger
- Left shift with orderly maturation
- Toxic changes (granulation, Dohle bodies)
- No circulating blasts
Treatment Plan
- Antibiotic therapy:
- Ceftriaxone + azithromycin for CAP coverage
- Adjust based on culture results
- Supportive care:
- Supplemental oxygen
- IV fluids
- Antipyretics
Teaching Points
- Leukocytosis with left shift indicates active bone marrow response to infection
- Toxic granulation and Dohle bodies are reactive changes supporting infection over malignancy
- The CBC differential should be evaluated as absolute counts, not just percentages
- Understanding the normal neutrophil maturation sequence (myeloblast → promyelocyte → myelocyte → metamyelocyte → band → segmented neutrophil) helps interpret the left shift
- The bone marrow releases increasingly immature forms when demand exceeds mature neutrophil supply