96. Jahrestagung der Deutschen Gesellschaft für Pathologie e. V ...
96. Jahrestagung der Deutschen Gesellschaft für Pathologie e. V ...
96. Jahrestagung der Deutschen Gesellschaft für Pathologie e. V ...
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Methods. We performed MCPyV-FISH of formalin fixed and paraffin<br />
embedded (FFPE) MCCs (n=62) on tissue microarrays (TMAs), determined<br />
the hybridization patterns and correlated these with qPCR data<br />
on the basis of a determined cut-off. MCPyV-FISH was established using<br />
the MKL-1 cell line which harbors integrated copies of MCPyV DNA.<br />
For MCPyV-qPCR a LT primer pair (Becker et al., 2009) was used on<br />
whole tissue sections.<br />
Results. MCPyV-FISH on FFPE MKL-1 cells revealed punctate signals<br />
compatible with viral integration. The MCPyV-FISH positive MCC cores<br />
(76%) mainly revealed two different signal patterns: a punctate pattern<br />
(85%) which correlated with a mo<strong>der</strong>ate relative viral abundance<br />
and in some areas the punctate pattern was combined with a diffuse pattern<br />
(15%) indicating the episomal presence of the virus which is linked<br />
to viral replication. A mixed hybridization pattern was associated with<br />
very high qPCR values. Comparing MCPyV-FISH and qPCR data the results<br />
highly correlated (83%) with the MCPyV positive evaluated group,<br />
whereas the negative group showed a concordance of 93%. The mean of<br />
the qPCR values of all MCPyV positive cores differed significantly from<br />
the negative cores (p=0.0076). In some tumor areas of one and the same<br />
patients the FISH signals were heterogeneous in intensity, pattern and<br />
nuclear localization.<br />
Conclusions. A strong correlation between MCPyV FISH and the relative<br />
MCPyV abundance by qPCR was detected. Thus, while presence<br />
of MCPyV can be verified by qPCR, the quality of the presence can be<br />
visualized by MCPyV specific FISH analysis. In this regard, MCPyV<br />
qPCR and MCPyV FISH are important complementary tools to gain<br />
maximum biological information of the presence of MCPyV in MCC<br />
and thus to further elucidate MCPyV related carcinogenesis.<br />
FR-007<br />
A novel BRAF mutation in a patient with metastatic melanoma<br />
R . Schnei<strong>der</strong>-Stock 1 , L . Heinzerling2 , E . Kämpgen2 , M . Erdmann2 , P . Keikavoussi2<br />
, A . Agaimy1 , A . Hartmann1 , G . Schuler2 1University of Erlangen-Nuremberg, Institute of Pathology, Erlangen,<br />
2University of Erlangen-Nuremberg, Department of Dermatology, Erlangen<br />
Aims. BRAF mutations in melanoma have been identified as a new target<br />
for therapy. The V600E mutation is found in 50–68% of malignant<br />
melanomas and can be specifically treated with e.g., the BRAF inhibitor<br />
PLX4032 now registered as Vemurafenib. We describe a patient with a<br />
metastasized nodular melanoma on the right lumbar region which was<br />
excised two years before but had already spread to the inguinal lymph<br />
nodes. Subsequently, the patient developed multiple metastases of the<br />
brain, metastases of the mediastinal, cervical, retroperitioneal, retrocrural,<br />
mesenterial, paraaortal and interaortocaval lymph nodes, in the<br />
liver, the stomach and the intestines. Previous therapy included lymphadenectomy,<br />
radiation therapy, hyperthermia, radiochemotherapy<br />
with temozolomide, sorafenib, fotemustine and paclitaxel/carboplatin.<br />
Despite these attempts he showed progressive disease and inclusion into<br />
a BRAF inhibitor study was consi<strong>der</strong>ed. Thus the tumor was sent for mutation<br />
analysis.<br />
Methods. Formalin-fixed and paraffin-embedded tumor sample was<br />
used for the extraction of genomic DNA. Mutational analysis was carried<br />
out by Pyrosequencing and for confirmation by ABI capillary sequencing<br />
of exon 15 of BRAF.<br />
Results. In this melanoma patient a new complex mutation was found<br />
in BRAF with base substitution of a valine residue at position 600 for<br />
glutamic acid (GTG GAA) and deletion of codon 601 (p.V600EK601del;<br />
c.1799_1801del3). With this mutation the patient did not qualify for the<br />
BRAF inhibitor study. The clinical course of the patient was rapidly progressive<br />
with various acute complications (renal insufficiency, ileus) and<br />
the patient deceased only 2 months after analysis of the mutation.<br />
Conclusions. The V600E mutation constitutively activates RAF/MEK<br />
signaling, a major driver of carcinogenesis in various malignancies.<br />
Other rather rare mutations like V600K, V600R or V600D might also<br />
cause this constitutive activation and are discussed to be correlated with<br />
a yet more aggressive behaviour. It is unclear whether the new mutation<br />
described in this case can be consi<strong>der</strong>ed for targeted BRAF inhibitor therapy.<br />
FR-008<br />
The aid of immunohistochemistry in differential diagnosis between<br />
benign and malignant phenotype of difficult melanocytic<br />
lesions<br />
T . Papadopoulos1 1Klinikum Nürnberg, Institute of Pathology, Nürnberg<br />
Aims. A panel of biological markers differentially expressed in common<br />
nevi, dysplastic nevi, Spitz nevi and malignant melanomas are introduced<br />
providing a potential tool to differentiate benign from malignant<br />
phenotype in difficult melanocytic lesions. The panel includes Cyclin<br />
D1, p16, p21 and p53.<br />
Methods. Cyclin D1 is markedly expressed in radial growth phase malignant<br />
melanomas but is negative in common nevi and in the deepest<br />
part of vertical growth phase melanomas as well. The cell cycle inhibitor<br />
p16 is positive in benign nevi and radial growth phase melanomas<br />
but becomes often negative as malignant melanoma progresses to the<br />
vertical growth phase. The cell cycle inhibitor p21 is positive in radial<br />
growth phase melanomas and in thin vertical growth phase melanomas<br />
but becomes negative in thick malignant melanomas. p21 is negative in<br />
common melanocytic nevi. Both cell cycle inhibitors p16 and p21 are<br />
upregulated in Spitz nevi and Spitzoid nevi. Finally, p53 is negative or<br />
positive at a very low level in melanocytic nevi. Its expression increases<br />
with tumor progression from dysplastic nevus to radial growth phase<br />
malignant melanoma and vertical growth phase malignant melanomas.<br />
Conclusions. This presentation demonstrates characteristic expression<br />
patterns of the above mentioned panel that may enable pathologists to<br />
differentiate benign from malignant melanocytic lesions even in cases<br />
when morphology by itself may not allow a clear classification of the melanocytic<br />
lesion.<br />
Notiz an die Gutachter des Abstracts: Der Abstract wurde nach Rücksprache<br />
und auf Wunsch von Prof . Meister (München) eingereicht . Vorgesehen ist ein<br />
etwa 15- bis 20-minütiger Vortrag, quasi als Review <strong>für</strong> die Immunhistochemie<br />
unklarer melanozytärer Läsionen .<br />
AG Dermatopathologie und AG Zytopathologie II –<br />
Endokrine Themen<br />
FR-009<br />
Epi<strong>der</strong>mal growth factor receptor mutation analysis in pleural<br />
effusions of advanced non-small cell lung cancer patients:<br />
When only cells are available<br />
A . Zimpfer1 , B . Schnei<strong>der</strong>1 , A . Polak1 , A . Bier2 , J . Kölbel1 , J .C . Virchow2 ,<br />
A . Erbersdobler1 1 2 University of Rostock, Institute of Pathology, Rostock, University of Rostock,<br />
Rostock<br />
Aims. Epi<strong>der</strong>mal growth factor receptor (EGFR) mutations are associated<br />
with an improved clinical outcome due to response to tyrosine kinase<br />
inhibitors in patients with non-small cell lung cancer (NSCLC). The<br />
overwhelming majority of bronchial cancer is diagnosed on often very<br />
limited tumor material which is also requested for secondary mutational<br />
analysis. This study assessed the feasibility of using PCR and gene-sequencing<br />
to screen for (EGFR) mutations in pleural effusions of advanced<br />
NSCLC patients.<br />
Der Pathologe · Supplement 1 · 2012 |<br />
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