Pitfalls in the detection of t(11;22) translocation by fluorescence in situ hybridization and RT-PCR: a single-blinded study.
The t(11;22) translocation is a diagnostic hallmark of various small round-cell tumors. This study correlates the performance of fluorescence in situ hybridization (FISH) and reverse transcription polymerase chain reaction (RT-PCR) in the detection of this translocation analyzing paraffin-embedded tissue specimens. As negative control samples, 10 cases of normal colon mucosa and 10 cases of colon carcinoma tissue were analyzed by FISH to determine a valid cutoff value for the diagnosis of a t(11;22) translocation. The mean number of false-positive nuclei differed significantly between disomic and polysomic control group cases (P=0.002). Therefore, the cutoff value was determined considering the pitfall polysomy. The analysis group consisted of 20 cases from the University of Düsseldorf and 10 cases from the University of Bonn. These cases were analyzed using PCR (Düsseldorf) and FISH (Bonn) using a single-blinded approach. Twenty-two cases (73.3%) were concordant in both methods. Five cases (16.7%) were discrepant, showing a positive result in FISH whereas PCR was negative. Three cases (10.0%) were analyzed by FISH, and PCR failed for nonoptimized tissue preparation. In conclusion, the detection of t(11;22) translocation is critically dependent on a thoroughly defined cutoff value for FISH and on appropriate tissue preparation for both methods. We recommend FISH as a sensitive screening tool in the detection of t(11;22) followed by subsequent PCR amplification of the specific chimeric transcript.
Friedrichs
Nicolaus
N
Institute of Pathology, University of Bonn Medical School, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany. nicolaus.friedrichs@ukb.uni-bonn.de
Kriegl
Lydia
L
Poremba
Christopher
C
Schaefer
Karl-Ludwig
KL
Gabbert
Helmut Erich
HE
Shimomura
Akihiko
A
Paggen
Ellen
E
Merkelbach-Bruse
Sabine
S
Buettner
Reinhard
R
D000328:Adult; D000368:Aged; D001483:Base Sequence; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000235:genetics; D016022:Case-Control Studies; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods* / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods* / Q000706:statistics & numerical data; D018228:Sarcoma, Small Cell / Q000175:diagnosis / Q000235:genetics; D016037:Single-Blind Method; D014178:Translocation, Genetic
D017931:DNA Primers