TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: LCMS    
Leukemia/Lymphoma Immunophenotyping, Flow Cytometry, Varies

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 (ALL) from acute myeloid leukemia (AML)

 

Immunologic subtyping of ALL

 

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

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

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, AML FISH 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 or if blasts and promyelocytes are CD34-negative and HLA-DR-negative.

 

The triage panel is initially performed to evaluate for monotypic B cells by kappa and lambda light chain expression, increased numbers of blast cells by CD34 and CD45 expression along with side scatter gating, and increased plasma cells by CD45 expression and side scatter gating. 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.

 

This panel, together with the provided clinical history and morphologic review, is used to determine what, if any, additional testing is needed for disease diagnosis or classification. If additional testing is required, it will be added per the 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 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 any of these tests. 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 as needed.

 

The following algorithms are available in Special Instructions:

-Bone Marrow Staging for Known or Suspected Malignant Lymphoma Algorithm

-Acute Myeloid Leukemia: Testing Algorithm

-Acute Myeloid Leukemia: Relapsed with Previous Remission Testing Algorithm

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

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Diagnostic hematopathology has become an increasingly complex subspecialty, particularly with neoplastic disorders of blood and bone marrow. While morphologic assessment of blood smears, bone marrow smears, and tissue sections remains the cornerstone of lymphoma and leukemia diagnosis and classification, immunophenotyping is a very valuable and important complementary tool.

 

Immunophenotyping hematopoietic specimens can help resolve many differential diagnostic problems posed by the clinical or morphologic features.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

This test will be processed as a laboratory consultation. An interpretation of the immunophenotypic findings and correlation with the morphologic features will be provided by a hematopathologist for every case.

Interpretation Provides information to assist in interpretation of the test results

Report will include a morphologic description, a summary of the procedure, the percent positivity of selected antigens, and an interpretive conclusion based on the correlation of the clinical history with the morphologic features and immunophenotypic results.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Specimens will be initially triaged to determine which, if any, of the immunophenotyping panels should be performed.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Jevremovic D, Dronca RS, Morice WG, et al: CD5+ B-cell lymphoproliferative disorders: Beyond chronic lymphocytic leukemia and mantle cell lymphoma. Leuk Res. 2010 Sep;34(9):1235-1238

2. Hanson CA: Acute leukemias and myelodysplastic syndromes. In: McClatchey KD, ed. Clinical Laboratory Medicine. Williams and Wilkins Inc;1994:939-969

3. Jevremovic D, Olteanu H: Flow cytometry applications in the diagnosis of T/NK-Cell lymphoproliferative disorders. Cytometry B Clin Cytom. 2019 Mar;96(2):99-115

4. Rosado FG, Morice WG, He R, Howard MT, Timm M, McPhail ED: Immunophenotypic features by multiparameter flow cytometry can help distinguish low grade B-cell lymphomas with plasmacytic differentiation from plasma cell proliferative disorders with an unrelated clonal B-cell process. Br J Haematol. 2015 May;169(3):368-376

5. Shi M, Ternus JA, Ketterling RP, et al: Immunophenotypic and laboratory features of t(11;14)(q13;q32)-positive plasma cell neoplasms. Leuk Lymphoma. 2018;59(8):1913-1919

6. Morice WG, Kimlinger T, Katzmann JA, et al: Flow cytometric assessment of TCR-V-beta expression in the evaluation of peripheral blood involvement by T-cell lymphoproliferative disorders: a comparison with conventional T-cell immunophenotyping and molecular genetic techniques. Am J Clin Pathol. 2004 Mar;121(3):373-383

7. Shi M, Jevremovic D, Otteson GE, Timm MM, Olteanu H, Horna P: Single antibody detection of T-Cell receptor alpha beta clonality by flow cytometry rapidly identifies mature T-Cell neoplasms and monotypic small CD8-positive subsets of uncertain significance. Cytometry B Clin Cytom. 2020 Jan;98(1):99-107

8. Jevremovic D, Olteanu H: Flow cytometry applications in the diagnosis of T/NK-cell lymphoproliferative disorders. Cytometry B Clin Cytom. 2019 Mar;96(2):99-115

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