Labs
Labs (1 of 40 slides)

Labs (2 of 40 slides)
Let’s begin with the patient’s CBC:
WBC (109/L) | Hb (g/dL) | MCV (fL) | PLT (109/L) |
---|---|---|---|
144 | 6.2 | 85 | 210 |
What’s what: WBC, white blood cell count; Hb, hemoglobin; MCV, mean cell volume; MCHC, mean cellular hemoglobin concentration; RDW-SD, red cell distribution width-standard deviation; platelets, PLT; Normal values: WBC 5-10 x 109/L, RBC 4-6 x 1012/L, Hb 12-16 g/dL, Hct 35-47%, MCV 80-100 fL, MCHC 32-36 g/dL, RDW-SD < 45%, platelets (PLT) 150-450 x 109/L
Labs (2 of 40 slides)
White cell differential – the percentages
White cell type | Percentage (%) |
---|---|
Neutrophils | 35 |
Bands | 18 |
Lymphocytes | 4 |
Monocytes | 5 |
Eosinophils | 2 |
Basophils | 8 |
Metamyelocytes | 9 |
Myelocytes | 15 |
Promyelocytes | 1 |
Other | 3 |
White cell differential – let’s calculate the absolute values
White cell type | Percentage (%) | Absolute count (x 109/L) |
---|---|---|
Neutrophils | 35 | 50 |
Bands | 18 | 26 |
Lymphocytes | 4 | 5.76 |
Monocytes | 5 | 7.2 |
Eosinophils | 2 | 2.9 |
Basophils | 8 | 11.5 |
Metamyelocytes | 9 | (we tend not discuss absolute counts) |
Myelocytes | 15 | (we tend not discuss absolute counts) |
Promyelocytes | 1 | (we tend not discuss absolute counts) |
Other | 3 | (we tend not discuss absolute counts) |


Therefore, the patient has neutrophilia, eosinophilia, basophilia, monocytosis and lymphocytosis!
If the patient had only 2% neutrophils, would they have neutropenia and be at increased risk for infection?
Can a patient with 99% neutrophils have neutropenia?
The patient has significant eosinophilia. Does that mean we should consider common causes of eosinophilia such as allergy, parasites and drug effect?
What more can you say about the patient’s white cell count and differential based solely on the lab values?
What does the differential diagnosis include at this point?
What would you look for on the peripheral smear to support a diagnosis of leukemoid reaction?
Let’s consider the peripheral smear findings according to cause of hyper-leukocytosis
Condition | Findings |
---|---|
Solid tumor | Activated neutrophils (toxic granulation, Dӧhle bodies, and cytoplasmic vacuoles); myelophthisic picture (nucleated red blood cells, granulocyte precursors, and teardrop-shaped erythrocytes) if bone marrow is infiltrated with tumor cells |
Infection | Activated neutrophils (toxic granulation, Dӧhle bodies, and cytoplasmic vacuoles); decreased platelets, schistocytes |
G-CSF | Activated neutrophils (toxic granulation, Dӧhle bodies, and cytoplasmic vacuoles) |
CML | Leukoerythroblastic blood picture with increased bands and more immature myeloid cells |
The patient’s smear appears as follows:


The molecular test for CML takes some time to come back. In the meantime, we need to consider treatment (see next section).