LLTOF - Overview: Leukemia and Lymphoma Phenotyping, Technical Only

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Test ID: LLTOF    
Leukemia and Lymphoma Phenotyping, Technical Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluating lymphocytoses of undetermined etiology


Identifying B- and T-cell lymphoproliferative disorders involving blood and bone marrow


Distinguishing acute lymphoblastic leukemia from acute myeloid leukemia (AML)


Immunologic subtyping of acute leukemias


Distinguishing reactive lymphocytes and lymphoid hyperplasia from malignant lymphoma


Distinguishing between malignant lymphoma and acute leukemia


Phenotypic subclassification of B- and T-cell chronic lymphoproliferative disorders, including chronic lymphocytic leukemia, mantle cell lymphoma, and hairy cell leukemia


Recognizing AML with minimal morphologic or cytochemical evidence of differentiation


Recognizing monoclonal plasma cells

Reflex Tests Lists test(s) that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial test(s)

Test IDReporting NameAvailable SeparatelyAlways Performed
FIRSTFlow Cytometry, Cell Surface, FirstNo, (Bill Only)No
ADD1Flow Cytometry, Cell Surface, AddlNo, (Bill Only)No
FCINTFlow Cytometry Interp, 2-8 MarkersNo, (Bill Only)No
FCIMSFlow Cytometry Interp, 9-15 MarkersNo, (Bill Only)No
FCINSFlow Cytometry Interp,16 or greaterNo, (Bill Only)No

Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.

Note: This test is only available to clients who have MayoAccess or MayoLink


The client is responsible for the interpretation and billing of the professional component; Mayo Clinic will bill the technical component only.


A triage panel is always performed. The panel is charged based on number of markers tested (FIRST for first marker, ADD1 for each additional marker). 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 (ADD1 if applicable).


For blood bone marrow, and fluid specimens, the triage panel evaluates 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 also includes antibodies to assess the number of CD3-positive T cells and CD16-positive/CD3-negative natural killer (NK) cells present. This 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.


For tissue specimens, the triage panel includes evaluation for monotypic B cells by kappa and lambda light chain expression, CD5, CD10, CD19, CD20, and CD23. Increased numbers of blasts and plasma cells are identified by CD45 expression along with 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.


This panel, together with the provided clinical history and morphologic review will determine if additional testing is required. If additional testing is needed, it will be added per algorithm to fully characterize a disease state with a charge per unique antibody tested.


Cases requiring the granular lymphocytic leukemia flow panel or V-beta panel will have an interpretation added and performed by a Mayo Clinic pathologist.


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


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) should be ordered as MYEFL / Myelodysplastic Syndrome by Flow Cytometry, Bone Marrow, not this test.


The following algorithms are available in Special Instructions:

-Malignant Lymphoma, Guideline for Bone Marrow Staging Studies

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

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test

Method Name A short description of the method used to perform the test


NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

Leukemia/Lymphoma; Tech Only Flow

Aliases Lists additional common names for a test, as an aid in searching

Tech Flow
Technical Only Flow
Tech Only Immunophenotyping
Technical Only Immunophenotyping
Virtual Flow
Leukemia Lymphoma