Is leukemia diagnosed with a bone marrow (BM) biopsy?

Diagnosis of Leukemia with Bone Marrow Biopsy

Yes, bone marrow biopsy is imperative for the final diagnosis of leukemia, though in some cases with sufficient peripheral blood blasts, diagnosis may be made without it. 1

Diagnostic Approach for Leukemia

Initial Assessment

• Peripheral blood (PB) evaluation is the first step, including complete blood count (CBC), differential count, and blood smear review 1
• If PB shows sufficient blasts, manual differential count, flow cytometry, fluorescent in situ hybridization (FISH), and next-generation sequencing (NGS) can be performed on the peripheral blood specimen 1
• Additional laboratory tests should include comprehensive metabolic panel, lactate dehydrogenase, phosphate, uric acid levels, and coagulation panel 1

Bone Marrow Examination

• Bone marrow (BM) aspiration and biopsy are typically required for definitive diagnosis of leukemia 1
• For acute leukemia diagnosis, a marrow or blood blast count of 20% or more is required (with some exceptions) 1
• Morphologic examination includes BM aspirate, touch imprint, cell clots, and core biopsy 1
• If BM aspiration is not possible (dry tap) or contraindicated, diagnosis can be rendered from peripheral blood if sufficient blasts are present 1, 2

Essential Components of Leukemia Diagnosis

Immunophenotyping

• Multicolor comprehensive flow cytometry panel is essential for diagnosing and classifying leukemia subtypes 1
• Flow cytometry should be performed on BM aspirate or PB if no BM aspirate is available 1
• Immunohistochemistry (IHC) studies may be necessary in some cases 1

Cytogenetics and Molecular Studies

• Conventional karyotyping must be performed on BM samples 1
• FISH studies are performed according to the suspected leukemia subtype 1
• Molecular studies (PCR, RT-PCR, NGS) are selective based on the subtype of leukemia 1, 3
• If BM cannot be obtained, peripheral blood can be used for these studies 1

Special Considerations

Acute Leukemia

• For acute myeloid leukemia (AML), cytochemical studies like myeloperoxidase (MPO) and nonspecific esterase (NSE) may be performed on BM or PB 1
• In acute lymphoblastic leukemia (ALL), specific genetic abnormalities require targeted testing 1

Chronic Leukemia

• In chronic myeloid leukemia (CML), BM biopsy is valuable in 25% of cases to identify disease phase or myelofibrosis 4
• For chronic lymphocytic leukemia (CLL), while not absolutely required at diagnosis according to guidelines, BM biopsy provides important clinical and biological information 5

When Bone Marrow Biopsy May Be Avoided

• When a complete panel of ancillary studies has been performed on a positive PB sample with sufficient blasts 1
• In cases where BM aspiration is contraindicated due to the patient's unstable clinical condition 1, 2
• When peripheral blood shows clear diagnostic features and sufficient material for all necessary studies 2

Long-term Monitoring

• BM examination remains the standard for response assessment and detection of measurable residual disease 2
• For monitoring of relapse, peripheral blood evaluation may be adequate in some cases, though BM testing offers superior sensitivity 2

Remember that while peripheral blood testing may sometimes be sufficient for initial diagnosis, bone marrow examination provides the most comprehensive assessment and remains the gold standard for leukemia diagnosis and classification 1, 2.