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Test Code CHRBM Chromosome Analysis, Hematologic Disorders, Bone Marrow

Useful For

Assisting in the diagnosis and classification of certain malignant hematological disorders in bone marrow specimens

 

Evaluating the prognosis in patients with certain malignant hematologic disorders

 

Monitoring effects of treatment

 

Monitoring patients in remission

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
_ML20 Metaphases, 1-19 No, (Bill Only) No
_M25 Metaphases, 20-25 No, (Bill Only) No
_MG25 Metaphases, >25 No, (Bill Only) No
_STAC Ag-Nor/CBL Stain No, (Bill Only) No

Testing Algorithm

This test includes a charge for cell culture of fresh specimens and professional interpretation of results. Analysis charges will be incurred for total work performed, and generally include 2 banded karyograms and the analysis of 20 metaphase cells. If no metaphase cells are available for analysis, no analysis charges will be incurred. If additional analysis work is required, additional charges may be incurred.

 

In addition to the cell culture without mitogens, a CpG-stimulated culture will be added and 10 additional cells will be analyzed for any specimen received from a patient age 30 or older with a reason for testing of chronic lymphocytic leukemia, small lymphocytic leukemia, lymphocytosis, Waldenstrom macroglobulinemia, or when test CLLDF / Chronic Lymphocytic Leukemia, Diagnostic FISH, Varies is ordered concurrently.

 

If this test is ordered and the laboratory is informed that the patient is on a Children's Oncology Group (COG) protocol, this test will be canceled and automatically reordered by the laboratory as COGBM / Chromosome Analysis, Hematologic Disorders, Children's Oncology Group Enrollment Testing, Bone Marrow.

 

For more information see:

-Acute Leukemias of Ambiguous Lineage Testing Algorithm

-Acute Myeloid Leukemia: Testing Algorithm

-Acute Myeloid Leukemia: Relapsed with Previous Remission Testing Algorithm

-Acute Promyelocytic Leukemia: Guideline to Diagnosis and Follow-up

-B-Lymphoblastic Leukemia/Lymphoma Algorithm

-Bone Marrow Staging for Known or Suspected Malignant Lymphoma Algorithm

-Multiple Myeloma: Laboratory Screening

-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation

-Mast Cell Disorder: Diagnostic Algorithm, Bone Marrow

-Eosinophilia: Bone Marrow Diagnostic Algorithm

Method Name

Cell Culture without Mitogens followed by Chromosome Analysis

Reporting Name

Chromosomes, Hematologic, BM

Specimen Type

Bone Marrow


Ordering Guidance


Chromosome analysis is not recommended for plasma cell neoplasms due to limited clinical utility.(1) If this test and a plasma cell FISH test (PCPDS / Plasma Cell Proliferative Disorder, High-Risk with Reflex Probes, Diagnostic FISH Evaluation, Bone Marrow; MSMRT / Mayo Algorithmic Approach for Stratification of Myeloma and Risk-Adapted Therapy Report, Bone Marrow; or MFCDF / Myeloma High Risk with Reflex Probes, Diagnostic FISH Evaluation, Fixed Cell Pellet) are ordered concurrently, this test will be canceled. If a secondary myeloid neoplasm is suspected and both this test and a plasma cell FISH (PCPDS/MSMRT/MFCDF) are needed, contact the Cytogenetics Communication Team at 800-533-1710 before sending the specimen.



Shipping Instructions


Advise Express Mail or equivalent if not on courier service.



Necessary Information


1. A reason for testing should be submitted with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.

2. A pathology and/or flow cytometry report may be requested by the laboratory to optimize testing and aid in interpretation of results.



Specimen Required


Container/Tube:

Preferred: Yellow top (ACD)

Acceptable: Green top (sodium heparin) or lavender top (EDTA)

Specimen Volume: 2 to 3 mL

Collection Instructions:

1. It is preferable to send the first aspirate from the bone marrow collection.

2. Invert several times to mix bone marrow.


Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Bone Marrow Ambient (preferred)
  Refrigerated 

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Chromosomal abnormalities play a central role in the pathogenesis, diagnosis, and treatment monitoring of many hematologic disorders. Cytogenetic studies on bone marrow may be helpful in many malignant hematologic disorders as the observation of a chromosomally abnormal clone may be consistent with a neoplastic process.

 

Certain chromosome abnormalities may help classify a malignancy. As examples, the Philadelphia (Ph) chromosome, also referred to as der(22)t(9;22)(q34;q11.2), is usually indicative of chronic myeloid leukemia (CML) or acute leukemia; t(8;21)(q22;q22) defines a specific subset of patients with acute myeloid leukemia; and t(8;14)(q24.1;q32) is associated with Burkitt lymphoma.

 

Cytogenetic studies are also used to monitor patients with hematologic neoplasia and may identify disease progression, such as the onset of blast crisis in CML, which is often characterized by trisomy 8, isochromosome 17q, and multiple Ph chromosomes.

 

Conventional chromosome studies of B-cell disorders are not always successful because B lymphocytes do not proliferate well in cell culture. The agent CpG 7909 (CpG) is a synthetic oligodeoxynucleotide that binds to the Toll-like receptor 9 (present on B cells, causing B-cell activation. In the laboratory setting, CpG may be used as a mitogen to stimulate B cells in patient specimens, thus allowing identification of chromosome abnormalities. CpG stimulation reveals an abnormal karyotype in approximately 80% of patients with chronic lymphocytic leukemia, and the karyotype is complex in 20% to 25% of cases. Several studies have reported that increased genetic complexity revealed by CpG-stimulated chromosome studies confers a less favorable time to first treatment, treatment response, and overall survival.

Reference Values

An interpretative report will be provided.

Interpretation

To ensure the best interpretation, it is important to provide some clinical information to verify the appropriate type of cytogenetic study is performed.

 

The following factors are important when interpreting the results:

-Although the presence of an abnormal clone usually indicates a malignant neoplastic process, in rare situations, the clone may reflect a benign condition.

-The absence of an abnormal clone may be the result of specimen collection from a site that is not involved in the neoplasm or may indicate that the disorder is caused by submicroscopic abnormalities that cannot be identified by chromosome analysis.

-On rare occasions, the presence of an abnormality may be associated with a constitutional abnormality that is not related to a malignant neoplastic process. Follow-up with a medical genetics consultation is recommended.

-On occasion, bone marrow chromosome studies are unsuccessful. If clinical information has been provided, there may be a fluorescence in situ hybridization study option that could be performed.

Cautions

In some cases, fluorescence in situ hybridization (FISH) studies may detect some disorders better than conventional chromosome studies:

-For plasma cell proliferative disorders such as multiple myeloma, FISH studies will detect chromosome anomalies with prognostic significance much more often than conventional chromosome studies. In this situation, PCPDS / Plasma Cell Proliferative Disorder, High-Risk with Reflex Probes, Diagnostic FISH Evaluation, Bone Marrow

 is recommended.

 

Interfering factors:

Technical:

-Insufficient bone marrow specimen

-Use of an improper anticoagulant or improperly mixing the blood with the anticoagulant

-Clotted bone marrow specimen

-Excessive transport time

-Exposure of the specimen to extreme temperature

-Not processing the bone marrow as indicated before shipping the specimen

-Not sending the first aspirate from the patient's bone marrow collection

 

Biological:

-Abnormalities missed due to sampling error

-Subtle structural chromosome abnormalities may not be detected by conventional chromosome analysis

-Neoplastic cells not dividing or not present in bone marrow

Method Description

A cell count is performed on the specimen to establish a plating volume. Based on the cell count, a corresponding volume of bone marrow is added to 2 culture flasks containing culture medium and incubated. In the harvest process, the cells are exposed to colcemid and hypotonic solution, and are then fixed. Metaphase cells are dropped onto microscope slides and are stained by G-banding. Other staining methods are employed as needed. Twenty metaphases are usually examined. If a clone is suspected, but not confirmed within 20 metaphases, 30 metaphases will be analyzed. Minimal evidence for the presence of an abnormal clone is defined as 2 or more metaphases with the same structural abnormality or chromosome gain (trisomy), or 3 or more metaphases lacking the same chromosome. All cells analyzed are captured using a computerized imaging system, and one or more karyograms from each clone are prepared to document the type of abnormality and to permit systematic interpretation of the anomalies.

 

When a specimen is received from a patient age 30 or older with a reason for testing of chronic lymphocytic leukemia, small lymphocytic lymphoma, lymphocytosis, or Waldenstrom macroglobulinemia, a CpG-stimulated culture will be added and 10 additional cells will be analyzed. Additional metaphases may be analyzed from the unstimulated or CpG-stimulated cell cultures if necessary to provide an accurate interpretation. All metaphases are captured using a computerized imaging system, and one or more karyograms from each clone are prepared to document the type of abnormality and to permit systematic interpretation of the abnormalities.(Arsham, Marilyn S., et al. eds. The AGT Cytogenetics Laboratory Manual. 4th ed. Wiley-Blackwell, 2017)

Day(s) Performed

Monday through Friday

Report Available

9 to 11 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88237, 88291-Tissue culture for neoplastic disorders; bone marrow, blood, Interpretation and report

88264 w/ modifier 52-Chromosome analysis with less than 20 cells (if appropriate)

88264-Chromosome analysis with 20 to 25 cells (if appropriate)

88264, 88285-Chromosome analysis with greater than 25 cells (if appropriate)

88283-Additional specialized banding technique (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CHRBM Chromosomes, Hematologic, BM 81861-7

 

Result ID Test Result Name Result LOINC Value
52358 Result Summary 50397-9
52360 Interpretation 69965-2
52359 Result 33893-9
CG774 Reason for Referral 42349-1
52361 Specimen 31208-2
52362 Source 31208-2
52364 Method 85069-3
52363 Banding Method 62359-5
54629 Additional Information 48767-8
52365 Released By 18771-6