Beijing Gobroad Boren Hospital Director Tong Chunrong: Full Analysis of Six Core Hematological Examinations
- Elva Chen
- 3 days ago
- 7 min read
Many family members of patients with hematological diseases share the same confusion during diagnosis: why are so many tests required? Blood draws, bone marrow punctures, repeated specimen submissions—what exactly does each test detect? Can fewer tests be done? In fact, the diagnosis of hematological diseases relies on comprehensive judgment from multiple examinations; a single test rarely delivers an accurate conclusion. Today, we invite Director Tong Chunrong from Beijing Boren Hospital to elaborate on the functions, advantages and limitations of each core laboratory test for reference and study.
In diagnosing hematological diseases, physicians order multiple tests not for redundant repetition, but because these technologies complement one another to form the basis for precise diagnosis.
Clinical evaluations are systematically carried out centered on five core laboratory divisions (naming varies across hospitals): Cell Morphology Laboratory, Pathological Diagnosis Laboratory, Flow Cytometry Laboratory, Cytogenetics Laboratory, and Molecular Diagnosis Laboratory. Corresponding tests include cell morphology and cytochemical staining, pathology and immunohistochemistry, flow cytometry, karyotype analysis, FISH, gene testing, etc.
Test 1: Cell Morphology & Cytochemical Staining
This is the most fundamental and rapid first step for diagnosing hematological malignancies. Simply put, bone marrow or peripheral blood is smeared onto glass slides, stained, and examined under a microscope to observe cellular morphology.
Advantages
Intuitive observation: Abnormal cells can be identified at a glance to narrow down differential diagnoses, an unmatched strength of other testing modalities.
Accurate cellular proportions: Morphology uses the initial bone marrow aspirate for direct slide preparation with minimal processing and negligible hemodilution. Subsequent tests (flow cytometry, gene testing, karyotyping) often rely on second or third aspirate pulls, which may underestimate the true proportion of malignant cells.
Strong suggestive value: Beyond identifying abnormal cells, morphological examination provides critical clinical clues. For example, abundant mitotic figures indicate rapid cell proliferation, prompting additional Ki-67 testing; smears may also reveal evidence of infectious pathogens for clinical reference.
Cost-effective & rapid: Preliminary results can be ready within 20–30 minutes with minimal costs, requiring only routine chemical dyes without complex reagents.
Disadvantages
The biggest limitation is heavy reliance on the examiner’s visual judgment and clinical experience. Diagnostic accuracy hinges entirely on the pathologist’s exposure to diverse clinical cases.
Example: Two morphologically similar cell populations may initially mimic lymphoma, yet the final diagnosis turns out to be hemorrhagic fever with renal syndrome (a viral infection). Inexperienced clinicians may misdiagnose and administer inappropriate lymphoma treatment, leading to severe clinical errors.
Test 2: Pathology & Immunohistochemistry
While morphological examination assesses individual cells on slides, pathology and immunohistochemistry analyze tissue blocks—such as lymph node or mass biopsy specimens fixed into paraffin sections for microscopic evaluation.
Advantages
Complete specimen preservation: Tissue samples are immediately fixed in formalin upon collection, fully retaining intracellular information that may be lost during processing for other assays.
Objective quantification of malignant cell percentage: Whole-tissue sections accurately reflect the true proportion of tumor cells within the lesion.
Diagnostic utility for inaccessible or rare large cell populations: Ideal for conditions where malignant cells are scarce or absent in bone marrow aspirates, including myelofibrosis, multiple myeloma, lymphoma (especially Hodgkin’s lymphoma), metastatic carcinoma, histiocytes, macrophages, and dendritic cells.
Direct visualization of tissue architecture to localize malignant infiltration: This is critical for lymphoma diagnosis. Many lymphomas are classified by their characteristic tissue arrangements—such as mantle cell lymphoma and follicular lymphoma—structural features only visible on pathological slides, undetectable via flow cytometry or gene testing alone.
Disadvantages
Prolonged turnaround time & operator-dependent accuracy: Specimens undergo fixation, embedding, sectioning and staining, a far lengthier workflow than blood smears; diagnostic quality depends heavily on the pathologist’s expertise.
Limited ability to distinguish benign/malignant status and cellular maturation in cases with intact tissue architecture or low malignant cell burden.
Sampling bias risk: Malignant cells suspended in body fluids cannot be captured via tissue biopsy; false-negative results occur if the biopsy fails to sample tumor-infiltrated regions.
Test 3: Flow Cytometry (FCM)
Flow cytometry is a core diagnostic technology for hematological malignancies. Unlike immunohistochemistry (which typically detects one marker per tissue section), flow cytometry suspends isolated cells to pass single-file through the instrument, simultaneously detecting dozens of biomarkers on each individual cell.
Advantages
Rapid, comprehensive profiling: Preliminary results available within 2 hours of specimen submission; tens of thousands to hundreds of thousands of cells are analyzed simultaneously for over six parameters per cell, delivering high sensitivity and multidimensional data.
Clear differentiation of benign/malignant cells, maturation stage and lineage origin:
Clinical example: Two patients present with 8% blasts on morphological review. Morphology alone cannot distinguish regenerative normal blasts (post-treatment bone marrow recovery) from residual leukemic blasts—flow cytometry readily differentiates the two. This explains why flow cytometry is the most widely used modality for minimal residual disease (MRD) monitoring.
Identification of immunotherapy targets & therapeutic response monitoring: Biomarkers including CD19, CD20 and BCMA are quantified via flow cytometry to confirm eligibility for CAR-T or antibody therapies. Serial flow testing tracks cellular changes during treatment to assess efficacy and detect target antigen loss.
Disadvantages
Loss of tissue architectural information: Tissue is dissociated into single cells, eliminating data on cellular arrangement, nodule formation and capsular invasion—critical structural features required for diagnosing Hodgkin’s lymphoma, which necessitates pathological correlation.
Cell loss during processing: Fragile cell populations such as diffuse large B-cell lymphoma (DLBCL) blasts and immature erythroid cells may rupture or wash away during staining and centrifugation, leading to underreported tumor cell percentages compared to morphology. This renders morphology superior for specific leukemias (e.g., erythroleukemia/M6) and myelodysplastic syndromes (MDS).
Strict specimen timelines: Biopsy, aspirate and body fluid samples must be processed and stained within 4 hours; declining cell viability invalidates results, requiring tight laboratory coordination.
High technical expertise threshold: Antibody panel design, marker combination and data interpretation demand extensive professional experience; identical specimens may yield divergent results between technicians of varying skill levels.
Less prognostic value than karyotyping and gene sequencing.
Test 4: Chromosome Karyotype Analysis
Chromosomes carry cellular genetic information; karyotype analysis microscopically evaluates numerical and structural chromosomal abnormalities (e.g., aneuploidy, translocations between two chromosomes).
Advantages
Independent diagnostic and prognostic value: Certain chromosomal aberrations serve as definitive diagnostic criteria for specific hematological diseases. For instance, the Philadelphia chromosome (9;22 translocation) pathognomonic for chronic myeloid leukemia (CML), and the 15;17 translocation defining acute promyelocytic leukemia (APL/M3). Chromosomal profiles also stratify patients into favorable, intermediate and high-risk prognostic subgroups to predict relapse risk.
Detection of uncharacterized genetic lesions: Karyotyping provides a full genomic "panoramic view", capturing chromosomal alterations even when the underlying mutated gene remains unidentified.
Disadvantages
Long turnaround time: Specimens require in vitro cell culture to induce mitosis, with results available in 7–14 days.
Heavy reliance on technician expertise: Chromosomal banding patterns are interpreted manually under microscopy, requiring highly trained personnel.
False negatives from non-proliferative malignant cells: Analysis requires metaphase cells; if tumor cells fail to divide in culture, chromosomal abnormalities remain undetected despite true disease burden.
Low analytical sensitivity: Only a limited number of dividing cells are examined; malignant cell populations below 5–10% are easily missed, making karyotyping unsuitable for MRD surveillance.
Test 5: FISH (Fluorescence In Situ Hybridization)
FISH can be regarded as a high-resolution refinement of karyotype analysis. Fluorescent-labeled probes target specific chromosomal or gene loci, generating visible fluorescent signals in abnormal cells.
Advantages
Independent diagnostic and prognostic utility: Confirms canonical chromosomal aberrations as diagnostic biomarkers.
Detection of submicroscopic lesions invisible to conventional karyotyping: Captures minute chromosomal rearrangements undetectable by light microscopy.
Mitosis-independent detection: Unlike karyotyping, FISH analyzes interphase cells without requiring cell culture and division.
High analytical sensitivity via large cell counting pools: Hundreds of cells are screened per assay, delivering more accurate quantification of malignant cells and superior MRD sensitivity versus karyotyping.
Rapid turnaround & reduced operator subjectivity: Results ready within 1–2 days; fluorescent signals are countable and objective, minimizing reliance on manual chromosomal band interpretation.
Retrospective testing capability: Archived bone marrow smears and paraffin tissue blocks can be reprocessed for FISH to confirm or rule out diagnoses.
Disadvantages
High probe cost; limited simultaneous target coverage: Each assay typically evaluates only 1–2 predefined genetic abnormalities.
Only detects known aberrations: Probes are designed against characterized lesions; novel, unreported genetic alterations cannot be identified—this is the core distinction from karyotyping’s whole-genome screening capacity.
Test 6: Gene Sequencing / Molecular Testing
Gene testing represents the most granular diagnostic tier, evaluating DNA and RNA-level abnormalities including gene mutations, fusion transcripts and aberrant gene expression.
Advantages
Independent diagnostic and prognostic value: Recurrent gene lesions (e.g., NPM1 mutation, double CEBPA mutation) are definitive diagnostic markers; molecular profiles enable precise risk stratification for clinical prognosis.
Detection of lesions invisible to karyotyping and FISH: Submicroscopic single-gene alterations that do not alter chromosomal banding or probe-binding sites are only identifiable via sequencing. Combined karyotype, FISH and molecular testing drastically improves prognostic stratification accuracy.
Faster turnaround than karyotyping: Results typically issued within 1–2 weeks.
Moderately reduced operator experience dependency: Standardized experimental workflows and strict quality control minimize subjective interpretation bias.
Gold-standard high-sensitivity MRD monitoring: For patients with trackable gene lesions, quantitative PCR or next-generation sequencing monitors residual disease with a detection limit of 1 in 10,000 to 1 in 100,000 cells—the most sensitive MRD modality available today.
Disadvantages
Stringent quality control across all experimental, sequencing and analytical stages: Multistep workflows and massive datasets render results vulnerable to error at any processing stage.
Limited diagnostic utility for genetically wild-type hematological malignancies: Not all hematological tumors carry characterized driver mutations; such cases require complementary morphology, flow cytometry and cytogenetic testing.
Conclusion
Readers may ask: are these six core examinations sufficient for full diagnosis?
Beyond the six MICM integrated diagnostic laboratory assays outlined above, two additional critical assessments support full-cycle hematological disease management:
Pathogen testing: Identifies bacterial, viral (e.g., EBV) and other infectious agents that modify disease progression.
Therapeutic drug monitoring & pharmacogenomic testing: Enables personalized medication regimens to maximize efficacy and minimize toxic adverse effects.
Crucially, no single test can independently resolve all clinical questions. Multidimensional integrated analysis of all diagnostic modalities enables clinicians to accurately stage disease and formulate individualized treatment plans. Understanding the purpose and limitations of each assay helps patient families approach diagnosis and treatment with greater composure and rationality.
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