FISH Is Superior to PCR in Detecting t(14;18)(q32;q21)-IgH/bcl-2 in Follicular Lymphoma Using Paraffin-Embedded Tissue Samples

Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905, USA.
American Journal of Clinical Pathology (Impact Factor: 3.01). 10/2005; 124(3):421-9. DOI: 10.1309/BLH8-MMK8-5UBQ-4K6R
Source: PubMed

ABSTRACT Detection of t(14;18)(q32;q21)-IgH/bcl-2, which is present in 70% to 95% of follicular lymphomas (FLs), might aid in diagnosing FL. The efficacy of routine polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques in detecting t(14;18) in paraffin-embedded tissue samples was compared on 5 normal tonsils and 28 FLs demonstrated to be t(14;18)+ by previous karyotyping. There was technical failure in 14 (50%) of the FLs by PCR, likely due to B-5 fixation, and 4 (14%) of FLs by FISH, likely due to advanced specimen age. In the remaining successful cases, 5 (36%) of 14 were positive by PCR and 24 (100%) of 24 were positive by FISH. All 5 normal tonsils were negative by both methods. FISH is superior to PCR for detecting t(14;18) from paraffin-embedded tissue samples because it is more sensitive and equally specific.

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    • "Accordingly , PCR testing for these mutations has become common practice both when first diagnosing many hematologic malignancies and when monitoring for minimal residual disease [Bonassi et al., 1995; Schuler and Dolken, 2006; Jolkowska et al., 2007; Gu et al., 2008]. However, even if the breakpoint locations are well known, as is the case with t(14;18), many reports maintain that FISH is superior to PCR in sensitivity and comparable to PCR in specificity [Einerson et al., 2005; Belaud-Rotureau et al., 2007; Gu et al., 2008]. FISHbased detection of translocations relies on fluorescent DNA probes that bind specifically to selected regions on one or both of the involved chromosomes. "
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