Test Catalog

Test ID: HLLFH    
Hematologic Disorders, Leukemia/Lymphoma; Flow Hold, Varies

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

This test is designed to delay the start of leukemia/lymphoma immunophenotyping until the preliminary assessment is completed. Specimens are held in the laboratory until noon (12 p.m. Central time) 2 days after the collection date. For testing to be cancelled, the client must call 800-533-1710. The testing process will be initiated and fully charged if no notification is received within this time period. To expedite the beginning of testing, call 800-533-1710.


The testing process begins with a screening panel. The screening panel will be charged based on the number of markers tested (FIRST for first marker, ADD1 for each additional marker). The interpretation will be based on markers tested in increments of 2 to 8, 9 to 15, or 16 and greater. In addition, reflex testing may occur to fully characterize a disease state or clarify any abnormalities from the screening test. Reflex tests will be performed at an additional charge for each marker tested (FIRST if applicable, ADD1 if applicable).


In addition to reflexing flow cytometric panels, AMLF / Acute Myeloid Leukemia (AML), FISH, Varies testing for PML-RARA translocation t(15;17),may be added by the Mayo Clinic pathologist to exclude acute promyelocytic leukemia if there is morphologic suspicion and/or blasts and promyelocytes are CD34 and HLA-DR-negative.


The triage panel is initially performed on peripheral blood, bone marrow, and fluid samples to evaluate for monotypic B cells by kappa and lambda light chain expression, increased numbers of blasts by CD34 and CD45 expression along with side scatter gating, and increased plasma cells by CD45 expression and side scatter gating. The panel can also evaluate T cells with CD3, CD5, and CD7. Additionally, viability is assessed on all tissue specimens using 7-AAD exclusion. The triage panel also includes antibodies to assess the number of CD3-positive T cells and CD16-positive/CD3-negative natural killer (NK) cells present. This triage panel also determines if there is an increase in the number of T cells that aberrantly coexpress CD16, an immunophenotypic feature of T-cell granular lymphocytic leukemia.


These panels, together with the provided clinical history and morphologic review, are used to determine what, if any, further testing is needed for disease diagnosis or classification. If additional testing is required, it will be added per algorithm to fully characterize a disease state with a charge per unique antibody tested.


If no abnormalities are detected by the initial panel, no further flow cytometric assessment will be performed unless otherwise indicated by specific features of the clinical presentation or prior laboratory results.


Additional fluorescence in situ hybridization (FISH) or molecular testing may be recommended by the Mayo pathologist to facilitate diagnosis. The referring physician or pathologist will be contacted to confirm the addition of these tests.

These include:

Cytogenetic FISH studies:

-CCND1/IGH translocation t(11;14), to exclude mantle cell lymphoma in cases of CD5+CD23- B-cell lymphoproliferative disorder.

-TCL-1 break-apart at 14q32, to exclude T-cell prolymphocytic leukemia in cases with CD4-positive T-cell lymphoproliferative disorder (phenotypic aberrancy or very tight CD4+ population with high CD4:CD8 ratio).

-MYC break-apart at 8q24, with or without IGH-BCL2 t(14;18) and BCL6 break-apart at 3q27, for suspected high grade B-cell lymphomas, based on morphologic assessment and immunophenotype (usually CD10-positive).


Molecular genetic studies:

T-cell receptor gene rearrangement to examine clonality of T cells in cases showing phenotypically aberrant T-cell population.


Cytochemical stains:

Confirmatory cytochemical stains are performed as needed.


The following algorithms are available in Special Instructions:

-Bone Marrow Staging for Known or Suspected Malignant Lymphoma Algorithm

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

Specimen Type Describes the specimen type validated for testing


Ordering Guidance

For bone marrow specimens being evaluated for possible involvement by a myelodysplastic syndrome (MDS) or a myelodysplastic/myeloproliferative neoplasm (MDS/MPN) including chronic myelomonocytic leukemia (CMML), order MYEFL / Myelodysplastic Syndrome by Flow Cytometry, Bone Marrow.


Bronchoalveolar lavage (BAL) and bronchial washings are not acceptable for this test due to the highly contagious nature of COVID-19 that could be present. The use of immunohistochemical (IHC) stains is encouraged for immunophenotyping in these specimen types.


This test is not appropriate for and cannot support diagnosis of sarcoidosis, hypersensitivity pneumonitis, interstitial lung diseases, or differentiating between pulmonary tuberculosis and sarcoidosis (requests for CD4/CD8 ratios). Specimens sent for these purposes will be rejected.

Additional Testing Requirements

For bone marrow testing, if cytogenetic tests are desired along with this test request, an additional specimen should be submitted. It is important that the specimen be obtained, processed, and transported according to instructions for the other test.

Shipping Instructions

Specimen must arrive within 72 hours for fluids or 96 hours for peripheral blood, bone marrow, and tissue.

Necessary Information

The following information is required before the specimen will be processed:

a. Pertinent clinical history including reason for testing or clinical indication

b. A pathology/diagnostic report including the client surgical pathology case number.

c. Clinical or morphologic suspicion

d. Specimen source

e. Date and time of collection

f. For tissue specimens: tissue type and location are required.

Specimen Required Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Due to specimen stability, spinal fluid is not appropriate for this test.


Submit only 1 of the following specimens:


Specimen Type: Blood


Preferred: Yellow top (ACD solution A or B)

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

Specimen Volume: 10 mL

Slides: Include 5- to 10-unstained blood smears, if possible.

Collection Instructions:

1. Send specimen in original tube. Do not transfer blood to other containers.

2. Label specimen as blood.

Specimen Stability Information: Ambient/Refrigerated <96 hours


Specimen Type: Bone marrow


Preferred: Yellow top (ACD solution A or B)

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

Specimen Volume: 1 to 5 mL

Slides: Include 5- to 10-unstained bone marrow aspirate smears, if possible.

Collection Instructions:

1. Submission of bilateral specimens is not required.

2. Label specimen as bone marrow.

Specimen Stability Information: Ambient/Refrigerated <96 hours


Specimen Type: Fluid

Sources: Serous effusions, pleural, pericardial, or abdominal (peritoneal fluid)

Container/Tube: Body fluid container

Specimen Volume: 20 mL

Collection Instructions:

1. If possible, fluids should be anticoagulated with heparin (1 U/mL of fluid).

2. The volume of fluid necessary to phenotype the lymphocytes or blasts in serous effusions depends upon the cell count in the specimen. Usually 20 mL of pleural or peritoneal fluid is sufficient. Smaller volumes can be used if there is a high cell count.

3. Label specimen with fluid type.

Specimen Stability Information: Refrigerated/Ambient <72 hours


Specimen Type: Tissue

Supplies: Hank's Solution (T132)

Container/Tube: Sterile container with 15 mL of tissue culture medium (eg. Hank's balanced salt solution, RPMI, or equivalent)

Specimen Volume: 5 mm(3) or larger biopsy

Collection Instructions:

1. Send intact specimen (do not mince).

2. Specimen cannot be fixed.

Specimen Stability Information: Ambient/Refrigerated <96 hours

Special Instructions Library of PDFs including pertinent information and forms related to the test


1. Hematopathology Patient Information (T676) in Special Instructions

2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.

Specimen Minimum Volume Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

Blood: 3 mL
Bone Marrow: 1 mL
Fluid: 5 mL
Tissue: 1 mm(3) or larger biopsy

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Bronchoalveolar lavage (BAL) or bronchial washings Fixed, paraffin-embedded, or minced tissue Reject

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen TypeTemperatureTimeSpecial Container