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Test ID COGBM Chromosome Analysis, Hematologic Disorders, Children's Oncology Group Enrollment Testing, Bone Marrow

Ordering Guidance

This test is only performed on specimens from pediatric patients being considered for enrollment in a Children's Oncology Group (COG) protocol. For all other patients, order CHRBM / Chromosome Analysis, Hematologic Disorders, Bone Marrow.

Shipping Instructions

Advise Express Mail or equivalent if not on courier service.

Necessary Information

1. A reason for referral, a flow cytometry and/or a bone marrow pathology report, and a Children's Oncology Group (COG) registration number and protocol number 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. If a child enrolled in the COG protocol has received an opposite sex bone marrow transplant prior to specimen collection, note this information on the request.

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

Specimen Required

Specimen Type: Bone marrow


Preferred: Yellow top (ACD)

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

Specimen Volume: 4 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.

Useful For

Evaluation of pediatric bone marrow specimens for chromosomal abnormalities associated with hematologic malignancies for diagnostic and prognostic purposes in patients being considered for enrollment in Children's Oncology Group clinical trials and research protocols using bone marrow specimens

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.


If this test is ordered and the laboratory is informed that the patient is not on a Children's Oncology Group (COG) protocol, this test will be canceled and automatically reordered by the laboratory as the corollary assay, CHRBM / Chromosome Analysis, Hematologic Disorders, Bone Marrow.


The following algorithms are available:

-Multiple Myeloma: Laboratory Screening

-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation

-Myelodysplastic Syndrome: Guideline to Diagnosis and Follow-up

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

-B-Lymphoblastic Leukemia/Lymphoma Algorithm

Method Name

Cell Culture without Mitogens followed by Chromosome Analysis

Reporting Name

COG-Chromosomes, Hematologic, BM

Specimen Type

Bone Marrow

Specimen Minimum Volume

2 mL

Specimen Stability Information

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

Clinical Information

Clonal chromosome abnormalities in bone marrow (or peripheral blood or tissue if bone marrow is not available) play a central role in the pathogenesis, diagnosis, and treatment monitoring of pediatric hematologic malignancies.


Characteristic chromosome rearrangements and copy number patterns may help classify a pediatric hematologic malignancy. For example, t(1;19)(q23;p13.3) is typically observed in B-cell acute lymphoblastic leukemia/lymphoma and t(8;21)(q22;q22) defines a specific subset of patients with acute myeloid leukemia; while t(7;14)(q35;q11.2) is associated with T-lymphoblastic leukemia/lymphoma. Confirmation of classic gene fusions associated with the above translocations together with evaluation for other recurrent abnormalities are available within the appropriate Children's Oncology Group (COG) fluorescence in situ hybridization (FISH) panels; COGBF / B-Lymphoblastic Leukemia/Lymphoma, Children's Oncology Group Enrollment Testing, FISH, Varies; COGTF / T-Cell Acute Lymphoblastic Leukemia (T-ALL), Children's Oncology Group Enrollment Testing, FISH, Varies; and COGMF / Acute Myeloid Leukemia (AML), Children's Oncology Group Enrollment Testing, FISH, Varies. Some rearrangements identified by chromosomal analysis may be extremely rare but are known recurrent entities for which the Mayo Clinic Genomics Laboratory has the most extensive catalogue of FISH testing to confirm the corollary gene fusions.


Metaphase FISH confirmation of classic translocations that are cryptic and not visually detectable by chromosome analysis [ie, t(12;21) associated with ETV6/RUNX1 fusion] is performed as required by COG and is included as part of the electronic case submission by the Mayo Clinic Genomics Laboratory to COG for central review.


Additional cytogenetic techniques such as chromosomal microarray (CMAH / Chromosomal Microarray, Hematologic Disorders, Varies) may be helpful to resolve questions related to ploidy (hyperdiploid clone vs doubled hypodiploid clone) or to resolve certain clonal structural rearrangements such as the presence or absence of intra-chromosomal amplification of chromosome 21 (iAMP21). If the expert cytogeneticist at Mayo Clinic reviewing this test's case feels microarray assay may be of benefit, the client will be contacted. For children in whom disease relapse or a secondary myeloid neoplasm is a concern and enrollment in a new COG protocol is being considered; this test is appropriate for bone marrow chromosome analysis.

Reference Values

An interpretative report will be provided.


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, we may have a fluorescence in situ hybridization study option that could be performed.

Clinical Reference

1. Dewald GW, Ketterling RP, Wyatt WA, Stupca PJ: Cytogenetic studies in neoplastic hematologic disorders. In: McClatchey KD, ed. Clinical Laboratory Medicine. 2nd ed. Williams and Wilkens; 2002:658-685

2. De Haas V, Ismaila N, Advani A, et al: Initial diagnostic work-up of acute leukemia: ASCO Clinical Practice Guideline Endorsement of the College of American Pathologists and American Society of Hematology Guideline. J Clin Oncol. 2019 Jan 20;37(3):239-253

3. Swerdlow SH, Campo E, Harris NL, et al, eds: WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. IARC Press; 2017

4. Arber DA, Borowitz MJ, Cessna M, et al: Initial diagnostic workup of acute leukemia: Guideline from the College of American Pathologists and the American Society of Hematology. Arch Pathol Lab Med. 2017 Oct;141(10):1342-1393

Day(s) Performed

Monday through Friday

Report Available

9 to 11 days

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test 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
COGBM COG-Chromosomes, Hematologic, BM 62386-8


Result ID Test Result Name Result LOINC Value
602306 Result Summary 50397-9
602307 Interpretation 69965-2
602308 Result 62356-1
GC022 Reason for Referral 42349-1
602309 Specimen 31208-2
602310 Source 31208-2
602311 Method 85069-3
602312 Banding Method 62359-5
602313 Additional Information 48767-8
602314 Released By 18771-6

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
ML20C COG Metaphases, 1-19 No, (Bill Only) No
M25C COG Metaphases, 20-25 No, (Bill Only) No
MG25C COG Metaphases, >25 No, (Bill Only) No
_STAC Ag-Nor/CBL Stain No, (Bill Only) No


If not ordering electronically, complete, print, and send a Children's Oncology Group Test Request (T829) with the specimen.