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

Test ID: TLYM    
T-Cell Lymphoma, FISH, Tissue

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

Detecting a neoplastic clone associated with the common chromosome abnormalities seen in patients with various T-cell lymphomas

 

Tracking known chromosome abnormalities and response to therapy in patients with T-cell lymphomas

 

Providing potentially prognostic information in patients with documented systemic anaplastic lymphoma kinase-negative anaplastic large cell lymphoma

 

Supporting the diagnosis of peripheral T-cell lymphoma when coordinated with consultation by anatomic pathology

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

This test does not include a pathology consultation. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge. Mayo Hematopathology Consultants are involved in both the pre-analytic (tissue adequacy and probe selection, when applicable) and post-analytic (interpretation of FISH results in context of specific case, when applicable) phases.

 

A charge and CPT code is applied for each probe set hybridized, analyzed, and reported.

 

Depending on the lymphoma subtype suspected, the most appropriate probes to order are listed in the Clinical Information.

 

If the patient is being tracked for known abnormalities, indicate which probes should be used.

 

Panel includes testing for the following abnormalities using the probes listed:

14q32.1 rearrangement, TCL1A

14q11.2 rearrangement, TRAD

-7/7q-/i(7q), D7S486/D7Z1

+8, D8Z2/MYC

2p23.2 rearrangement, ALK

3q28 rearrangement, TP63 and TBL1XR1/TP63 (only performed when necessary to resolve or confirm TP63 rearrangement concerns)

6p25.3 rearrangement, IRF4 (DUSP22

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

T-cell malignancies account for approximately 12% of all non-Hodgkin lymphomas. There are several subtypes of T-cell neoplasms: T-cell acute lymphoblastic leukemia (T-ALL), T-cell prolymphocytic leukemia (T-PLL), T-cell large granular lymphocytic leukemia (T-LGL), anaplastic large cell lymphoma (ALCL), peripheral T-cell lymphoma (PTCL), and various other cutaneous, nodal, and extrandodal lymphoma subtypes. The 2 most prevalent lymphoma subtypes are unspecified peripheral T-cell lymphoma (3.7%) and ALCL (2.4%).

 

A few common chromosome abnormalities are associated with specific T-cell lymphoma subtypes, including:

Common Chromosome Abnormalities in T-cell Lymphomas

 Lymphoma Type

 Chromosome Abnormality

  FISH Probe

Anaplastic Large cell lymphoma (ALCL)

2p23 rearrangement

3’/5’ ALK

3q28 rearrangement

5’/3’ TP63

6p25.3 rearrangement

5’/3’ IRF4 (DUSP22)

T-cell prolymphocytic leukemia (TPLL)

inv(14)(q11q32)/ t(14;14)(q11;q32)

 5’/3’ TCL1A

5’/3’ TRAD

Hepatosplenic T-cell lymphoma (HSTL)

Isochromosome 7q

D7S486/D7Z1

trisomy 8

D8Z2/MYC

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.

Interpretation Provides information to assist in interpretation of the test results

A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for any given probe.

 

Detection of an abnormal clone is supportive of a diagnosis of a T-cell lymphoma. The specific abnormality detected may help subtype the neoplasm.

 

The absence of an abnormal clone does not rule out the presence of a neoplastic disorder.

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

This test is not approved by the U.S. Food and Drug Administration and it is best used as an adjunct to existing clinical and pathologic information.

 

Fixatives other than formalin (eg, Prefer, Bouin) may not be successful for FISH assays.

 

Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.

Supportive Data

Each probe was independently tested on a set of formalin-fixed, paraffin-embedded tissue specimens from patients diagnosed with a T-cell lymphoma and noncancerous lymph node specimens. Normal cutoffs were calculated based on the results from 25 normal specimens. For each probe set, a series of chromosomally abnormal specimens were evaluated to confirm each probe set detected the anomaly it was designed to detect.

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

1. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Edited by SH Swerdlow, E Campo, NL Harris. IARC, Lyon 2017

2. Feldman AL, Law M, Remstein ED, et al: Recurrent translocations involving the IRF4 oncogene locus in peripheral T-cell lymphomas. Leukemia 2009;23:574-580

3. Feldman AL, Dogan A, Smith Dl, et al: Discovery of recurrent t(6:7)(p25.3;q32.3) translocations in ALK-negative anaplastic large cell lymphomas by massively parallel genomics sequencing. Blood 2011 Jan 20;117(3):915-919

4. Parilla Castellar ER, Jaffe ES, Said JW, et al: ALK-negative anaplastic large cell lymphoma is a genetically heterogeneous disease with widely disparate clinical outcomes. Blood 2014 Aug 28;124(9):1473-1480

5. Vasmatzis G, Johnson SH, Knudson RA, et al: Genomics-wide analysis reveals recurrent structural abnormalities of TP63 and other p53-releated genes in peripheral T-cell lymphomas. Blood 2012 Sep 13;120(11):2280-2289