From the Guidelines
Laboratory findings for a diagnosis of leukemia typically include abnormal complete blood count (CBC) results, peripheral blood smear examination, bone marrow aspiration and biopsy, flow cytometry, cytogenetic analysis, and molecular testing. The most recent and highest quality study, 1, published in 2023, emphasizes the importance of cytogenetics, FISH, and RT-PCR in diagnosing chronic myeloid leukemia.
Key laboratory findings may include:
- Abnormal CBC results showing elevated, decreased, or immature white blood cells
- Leukocytosis (increased white blood cell count)
- Anemia (low hemoglobin/red blood cells) and thrombocytopenia (low platelets)
- Peripheral blood smear examination revealing blast cells or abnormal lymphocytes
- Bone marrow aspiration and biopsy showing hypercellularity with >20% blasts for acute leukemias
- Flow cytometry identifying specific cell markers to classify leukemia type
- Cytogenetic analysis and molecular testing detecting chromosomal abnormalities and genetic mutations like BCR-ABL in CML or PML-RARA in APL
Additional tests, such as lumbar puncture, comprehensive metabolic panel, and lactate dehydrogenase (LDH) levels, may also be necessary to determine the specific type of leukemia and guide treatment selection, as recommended by 1 and 1. The diagnosis of CLL, for example, requires the presence of ≥5000 B lymphocytes/µl in the peripheral blood for at least 3 months, as stated in 1 and 1.
It is essential to note that the diagnosis and management of leukemia require a comprehensive approach, incorporating clinical, laboratory, and molecular findings, as highlighted in 1 and 1. The most critical aspect of diagnosing leukemia is to determine the specific type, which is crucial for selecting the appropriate treatment.
From the Research
Lab Findings for Leukemia Diagnosis
The diagnosis of leukemia involves a combination of clinical information, morphologic evaluation, immunophenotyping, karyotype analysis, and molecular genetic testing 2. The lab findings for leukemia diagnosis may include:
- Bone marrow biopsy or peripheral blood smear to confirm the diagnosis 3
- Complete blood count (CBC) to assess bone marrow function and unintentionally detect different types of leukemia 4
- Immunophenotyping to identify the type of leukemia cells 2, 5
- Karyotype analysis to detect chromosomal abnormalities 2
- Molecular genetic testing to detect specific genetic mutations 2
Types of Leukemia and Lab Findings
The lab findings may vary depending on the type of leukemia, such as:
- Acute lymphoblastic leukemia (ALL): may show lymphoblasts on peripheral blood smear and bone marrow aspirate 5
- Acute myeloid leukemia (AML): may show myeloblasts on bone marrow biopsy and immunophenotyping 5
- Chronic myeloid leukemia (CML): may show the presence of BCR/ABL1 in the blood and/or bone marrow 6
- Chronic lymphocytic leukemia (CLL): may show lymphocytosis on peripheral blood smear 3
Importance of Lab Findings in Leukemia Diagnosis
The lab findings are essential in establishing the diagnosis of leukemia and guiding treatment decisions 2, 6, 3. The initial diagnosis and subsequent monitoring of leukemia require a comprehensive approach, including laboratory testing, to ensure accurate diagnosis and effective treatment 2, 6, 3.