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Interpretive Handbook

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Test 80027:
B-Cell Lymphoma, FISH, Tissue

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

Mature B-cell lymphoma can be low grade, intermediate grade, or high grade, and the prognosis and clinical course are highly variable. Genetic abnormalities have emerged as one of the most important prognostic markers in B-cell lymphomas and can aid in diagnosis. Several chromosome anomalies and variants of these anomalies have been associated with various lymphoma subtypes (see table below). Unfortunately, conventional chromosome studies cannot be employed on paraffin-embedded tissue, and molecular genetic analyses are often problematic in the study of lymphomas. Fluorescence in situ hybridization (FISH) permits the detection of abnormal gene associated with various chromosome translocations and inversions in B-cell lymphoma (see table below).  

Common Chromosome Anomalies in B-Cell Lymphomas

Lymphoma Type

Chromosome Anomaly

FISH Probe

Burkitt (pediatric)

8q24.1 rearrangements

MYC

t(8;14)(q24.1;q32)

MYC/IGH

t(8;22)(q24.1;q11.2)

MYC/IGL

--reflex: 22q11.2 rearrangement

IGL

Mantle Cell

t(11;14)(q13;q32)

CCND1/IGH

Follicular

t(14;18)(q32;q21)

IGH/BCL2

Diffuse large B cell, Burkitt-like "double-hit"

 

3q27 rearrangements

BCL6

t(14;18)(q32;q21)

IGH/BCL2

8q24.1 rearrangements

MYC

t(8;14)(q24.1;q32)

MYC/IGH

t(8;22)(q24.1;q11.2)

MYC/IGL

--reflex: 22q11.2 rearrangement

IGL

MALT Lymphoma

t(11;18)(q21;q21)

BIRC3/MALT1

--reflex: t(14;18)(q32;q21)

 IGH/MALT1

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 B-cell lymphomas

 

Tracking known chromosome abnormalities and response to therapy in patients with B-cell neoplasms

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 B-cell lymphoma. The specific anomaly 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 FDA-approved 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.  

 

Although FISH testing will not be rejected due to nonformalin fixation, results may be compromised.

 

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.

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.

Clinical References Provides recommendations for further in-depth reading of a clinical nature

WHO Classification of Tumour of Haematopoietic and Lymphoid Tissues. Edited by SH Swerdlow, E Campo, NL Harris. IARC, Lyon 2008, pp 214-217, 220-226, 229-237, 262-278