96. Jahrestagung der Deutschen Gesellschaft für Pathologie e. V ...

Abstracts
were LA-positive for RealTime-HPV/HC2 targeted HPV types: 27 of 33
RealTime-HPV-pos/HC2-neg and 11 of 40 RealTime-HPV-neg/HC2pos
cases. 35 cases were LA-negative: 6 of 33 RealTime-HPV-pos/HC2neg
and 29 of 40 RealTime-HPV-neg/HC2-pos cases. In 280 histology
confirmed cases overall-agreement between RealTime-HPV and HC2
was 82.5%. Detection rates for CIN2+ and CIN3+ were 90.6% and 90.7%
with RealTime-HPV and 89.3% and 88.3% with HC2, respectively. A high
correlation of HPV16/18 positivity with RealTime-HPV and increasing
histological severity was found.
Conclusions. Clinical performance of RealTime-HPV in routine specimens
was comparable to that of HC2. Discrimination of HPV 16/18 from
other HR HPV types provides additional information for risk stratification.
SA-P-041
FISH analysis does neither reveal genomic ETV1 amplification nor
break-apart in gastrointestinal stromal tumors
E . Wardelmann1 , S . Huss1 , R . Menon2 , F . Göke2 , G . Kristiansen2 , R . Buettner1 , S .
Perner2 1 2 University Hospital Cologne, Institute of Pathology, Köln, University Hospital
Bonn, Institute of Pathology, Bonn
Aims. Gastrointestinal stromal tumors (GISTs) are the most common
mesenchymal tumors of the gastrointestinal tract. Recently the transcription
factor ETV1 was shown to be highly expressed in GISTs both
at transcript and protein levels. ETV1 is a member of ETS family of transcription
factors. The ETS family members share an evolutionary highly
conserved 80-amino-DNA binding domain and individual proteins of
this family are capable of regulating gene promoter activity. Chi et al.
reported that ETV1 is highly expressed in those ICCs, from which GISTs
arise. Taken together, they propose that GISTs originate from ICCs with
high endogenous level of ETV1 when an oncogenic activation via KIT or
PDGFRA mutation occurs. However, they could not detect any genomic
alteration leading to the high ETV1 expression performing FISH analysis
on four GIST samples and two GIST cell lines. The present study was
accomplished to evaluate in a larger cohort whether an ETV1 amplification
or break apart might represent the genomic alteration causing the
reported ETV1 expression.
Methods. For the ETV1 amplification assay, we used the commercially
available Chromosome 7 reference probe CEP 7 (D7Z1), spanning the
region 7p11.1–q11.1. The target probe was located on the ETV1 locus at
7p21.2. The target probe was labelled with biotin to produce a red signal
using CTD-2220I3 BAC clone. For the ETV1 break-apart assay, we
used BAC clones CTD-222013 for centromeric labelling with biotin and
RP-11769K2 for telomeric labelling with digoxigenin. BAC clones were
obtained from Invitrogen (Invitrogen, CA, USA).
Results. We performed FISH analysis on 140 GIST patients using tissue
micro arrays. Neither ETV1 amplification nor break apart was detectable.
Conclusions. The present study ensures that neither a genomic ETV1 amplification
nor a break apart is found in GISTs. We conclude that not
genetic aberrations but rather upregulation of ETV1 due to high KIT
receptor levels are responsible for the high ETV1 expression in GISTs.
152 | Der Pathologe · Supplement 1 · 2012
SA-P-042
A new whole genome amplification method for studying clonal
evolution patterns in malignant colorectal polyps
D . Hirsch1 , J . Camps1 , S . Varma2 , R . Kemmerling3 , T . Ried1 , T . Gaiser1 1Section of Cancer Genomics, Genetics Branch, Center for Cancer Research,
National Cancer Institute, National Institutes of Health, Bethesda, United
States, 2HiThru Analytics, Bethesda, United States, 3University Hospital
Salzburg of the Paracelsus Private Medical University, Institute of Pathology,
Salzburg, Austria
Aims. The transition of normal colonic epithelium to adenoma and invasive
carcinoma is defined by chromosomal aberrations. To identify the
genetic drivers involved in this progression in samples from individual
patients, we applied array comparative genomic hybridization (aCGH) to
13 formalin-fixed paraffin-embedded (FFPE) samples of early, localized
human colon adenocarcinomas arising in high-grade adenomas (so called
“malignant polyps”). These lesions are small and hence the amount of
DNA limited. Additionally, the quality of the DNA is compromised due
to the fragmentation as a consequence of formalin fixation. To overcome
these problems, we optimized a newly developed isothermal whole genome
amplification system (NuGEN Ovation® WGA FFPE System).
Methods. DNA was isolated from the FFPE blocks of 13 malignant polyps,
each consisting of areas of adenoma and carcinoma. Starting with
100 ng of FFPE DNA, the amplification system produced 4.01±0.29 µg
(mean ± standard deviation) of DNA. The samples were then analyzed
using Agilent SurePrint G3 Human CGH Microarrays 4×180K.
Results. Genomic imbalances were conserved in this procedure as assessed
by comparing amplified and unamplified FFPE DNA using aCGH.
The excellent quality of amplified DNA was further indicated by a high
signal-to-noise ratio and a low derivative log2 ratio spread. Both, the
amount of amplified DNA and aCGH performance were independent
from the age of the FFPE block and the associated degradation of the
extracted FFPE DNA. We observed losses of chromosome arms 5q and
18q in the malignant polyp samples, while the embedded early carcinomas
revealed losses of 8p, 17p, and 18, and gains of 7, 8q, 13, and 20.
Aberrations detected in the adenoma were invariably maintained in the
embedded carcinomas.
Conclusions. In conclusion, this approach demonstrates that using isothermally
whole genome amplified FFPE DNA is technically suitable for
aCGH. Besides demonstrating clonal origin of the adenoma and carcinoma
part within a malignant polyp, the gain of chromosome arm 20q
was an indicator for progression from adenoma to carcinoma in malignant
polyps.
SA-P-043
Dissimilarities of colorectal (CRAIT) and sinonasal adenocarcinoma
(SNAIT) of intestinal type
K . Donhuijsen1 , I . Kollecker1 , H . Hannig1 , H .-G . Schroeder2 1Academical Hospital Braunschweig, Department of Pathology, Braunschweig,
2Academical Hospital Braunschweig, Department of Otorhinolaryngology,
Braunschweig
Aims. SNAIT and CRAIT are considered to be nearly identically whereas
an uninformed pathologist would diagnose an endonasal metastasis of a
CRAIT instead of a primary of the inner nose. However, in a closer look
are there discrepancies to detect by morphology, immunohistology and
molecular results?
Methods. Fifty consecutive cases of SNAIT and CRAIT were compared
with regard to morphological criteria as subtype, histological inhomogeneity,
mucin production, desmoplastic reaction and vascular invasion.
Further the expression of CDX2, CK7, CK20, Synaptophysin, p53, Ki67,
were compared and also the molecular status (30 cases) by PCR for K-
RAS, b-raf, EGFR and p53.
Results. SNAIT and CRAIT are histologically quite similar but not identical:
adenomatous precursor lesions are absent. Tumor inhomogeneity