Oskar Koperek

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BACKGROUND Since the first description of Central neurocytomas (CNs) as a benign tumor entity in 1982, there has been great enthusiasm regarding the benign course and the curative surgical approach to this disease. The current study was performed to investigate the frequency of disease recurrence during long-term follow-up. METHODS A retrospective(More)
OBJECTIVE To determine risk factors for presence of lymph node or distant metastases in patients with follicular thyroid cancer (FTC) at the time of diagnosis and whether there is a relationship between the type of tumor invasion and metastases. SUMMARY BACKGROUND DATA FTC often presents distant metastases at the initial diagnosis. As distant metastases(More)
AIMS To evaluate the reliability of desmoplasia as a reproducible morphological parameter indicating the metastatic potential of medullary thyroid carcinoma (MTC). METHODS AND RESULTS One hundred and twenty cases of MTC of the Medical University of Vienna, Austria and 76 cases from the School of Medicine of Marseille, France were analysed for the presence(More)
Clear cell histology is the hallmark of oligodendroglioma (OG) but also characterizes clear cell ependymoma (CCE) and central neurocytoma (CN). Immunohistochemistry for glial and neuronal proteins may support differential diagnosis. We investigated systematically diagnostic value and limits of immunohistochemistry using representative tumor specimens (>1 cm(More)
Sporadic, acquired, and genetic human prion diseases are characterized neuropathologically by distinct deposition patterns of the abnormal, disease-associated form of the prion protein (PrPsc). In addition to mutations in the prion protein gene (PRNP), PrPsc immunostaining patterns correlate with molecular phenotypes of prion diseases defined by the PRNP(More)
Human prion diseases like Creutzfeldt-Jakob disease are infectious, inherited, or sporadic neurodegenerative disorders, characterized by the accumulation of an abnormal isoform of the host-encoded prion protein. This affects nervous tissue in sporadic Creutzfeldt-Jakob disease and, additionally, in lymphoid tissue in bovine spongiform encephalopathy-linked(More)
Meningiomas of the ventricle system are extremely rare. We report on a series of 16 intraventricular meningiomas (IVMs) treated at our institution between 1980 and 2004, with a special interest on the surgical outcome of using the intra/interparietal and parieto-occipital approach and the benefits of neuronavigation. A retrospective analysis of the medical(More)
The V600E mutation of the B-type Raf kinase (BRAF) gene is a common event in papillary thyroid carcinoma (PTC) and seems to play a key role in the development and progression of this disease. We evaluated the expression of the mutated BRAF V600E protein in 144 cases of PTC using a novel mutation-specific antibody. Seventy-six PTCs (52.8%) showed unequivocal(More)
Medullary thyroid carcinomas (MTCs) are mostly aggressive but slowly growing malignant tumours that metastasize early to loco-regional lymph nodes. Desmoplastic stroma reaction is a strong risk factor associated with lymph node metastases. We evaluated immunohistochemically the expression of two hypoxia-associated proteins, carbonic anhydrase IX (CAIX) and(More)
A European Federation of Cytology Societies (EFCS) working party of 28 members from 14 European countries met at the European Congress of Cytology in Lisbon in September 2009, with two observers from the USA, to discuss the need for standardising thyroid FNA nomenclature in the light of the National Institute of Cancer (NCI) recommendations resulting from(More)