Blood work
Blood work helps to confirm the diagnosis in diseases like leukemia, but can also detect critical abnormalities which require treatment - such as severe anemia and thrombocytopenia.
Leukemia:
- WBC - may be increased, decreased or normal
- Platelets - often decreased
- Hemoglobin - Often decreased
- Differential - often neutropenia & blasts
- 10% of patients have “normal” CBC
- Usually cannot diagnose type of leukemia from CBC
Below is a normal blood smear:
Children with leukemia can present with leukocytosis
- White blood cell count greater than 11,000 per mm3 (11 X 109 /L) is
- Frequently found on routine testing
- Usually due to infection or inflammation
- Rarely due to primary bone marrow disease
Below is a blood smear in leukemia. The blue cells are leukemic blast cells:
Here are links to three very clear articles from "The American Family Physician"
1. Describing the expected levels of Hb for children of different ages and the causes of childhood anemia.
2. Describing the investigation of leukocytosis
Basics of Assessment of the child with Leukocytosis
3. Evaluation of the child with purpura and thrombocytopenia
Evaluating the Child with purpura
Biochemistry
There may be significant biochemical abnormalities associated with childhood malignancy.
Biochemical abnormalities seen in acute leukemia:
| Possible abnormality | Cause | |
| Potassium | Increased | cell lysis |
| Phosphorus | Increased | cell lysis |
| Uric acid | Increased | cell lysis |
| Calcium | Decreased | binds with phosphorus |
| Creatinine | Increased | risk of renal failure |
| LDH | Increased | increased cell turnover |
