Biomedical subjects

Oskar Koperek

Publications and source records attributed to Oskar Koperek.

5 recordsLinked to original sources

PubMed2005

Intraventricular meningiomas: a report of 16 cases.

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/inter-parietal and parieto-occipital approach and the benefits of neuro-navigation. A retrospective analysis of the medical files for clinicoradiological findings, surgical interventions and surgical outcome was carried out. In 16 IVM patients with a female/male ratio of 11:5, age ranged from 24 years to 84 years (median 44 years). Duration of symptoms ranged from a few days to several years, and the cardinal symptoms were signs of increased intracranial pressure (86%), followed by corticospinal tract signs (43%), visual field defects (36%), cognitive changes (29%) and seizures (7%). The majority of tumours was located in the trigone (88%), and one was found in each the temporal horn and in the fourth ventricle. Tumour size ranged from 2.5 cm to 8 cm (median 5 cm), and the radiological appearance was uniform. The neuropathological workup revealed most IVMs as meningothelial, transitional (mixed) or lymphoplasmacyte-rich meningiomas (81%). Three tumours were classified as atypical (19%) and the MIB-1 proliferation index ranged from 1% to 40%. Complete resection was possible in all but one case. The trigonal IVMs were resected via an intraparietal/inter-parietal or parieto-occipital approach, and neuro-navigation was used in eight tumours. We encountered one perioperative death and one severely disabled patient. All other patients had a Glasgow outcome scale score of 5, and most of the pre-existing symptoms disappeared or improved after surgery. IVMs are a surgically curable tumour entity in most cases. The intraparietal/inter-parietal and parieto-occipital approach is very safe, and neuro-navigation allows early devascularisation of the tumour.

Adult↗

PubMed2005

Prion disease with a 144 base pair insertion: unusual cerebellar prion protein immunoreactivity.

Sporadic, acquired, and genetic human prion diseases are characterized neuropathologically by distinct deposition patterns of the abnormal, disease-associated form of the prion protein (PrP(sc)). In addition to mutations in the prion protein gene (PRNP), PrP(sc) immunostaining patterns correlate with molecular phenotypes of prion diseases defined by the PRNP polymorphism at codon 129 and with protease-resistant PrP classified by Western blotting. Some point or insertional PRNP mutations share similar clinical and neuropathological phenotypes, whereas others show great variability even within the same family. Here we report a patient who presented clinically as sporadic Creutzfeldt-Jakob disease (CJD). Histologically moderate spongiform change was seen in cerebral and cerebellar cortical areas. Neuronal loss was restricted mainly to the occipital cortex and the basal ganglia. Surprisingly, numerous eosinophilic globular structures were noted in the molecular layer and the parahippocampal gyrus. These globules showed intense PrP immunopositivity using anti-PrP antibodies against different epitopes. They were stained with PAS but lacked congophilia and birefringence in polarized light. Ultrastructurally, globules were composed of 21-nm-thick intermingled filaments without dense core. Genetic analysis revealed a PRNP 144 base pair insertion. Our case reinforces the importance of molecular genetic diagnosis, especially in those patients who lack a family history of prion disease and show unusual neuropathological changes. It also widens the phenotypic spectrum of prion diseases. The phenotypic variability within the same mutation suggests further, yet uncharacterized, genetic or epigenetic influence on phenotype in these diseases.

Aged↗

PubMed2005

Recurrent central neurocytomas.

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 analysis of the medical files with emphasis on clinicoradiologic findings and histologic and immunohistochemical features was performed. RESULTS: Between 1985-2003. surgical resection was performed in 14 patients with CNs ages 16-43 years (7 were female and 7 were male). Two patients (14%) died postoperatively and one patient had a malignant disease course (7%). In the remaining 11 patients, one patient with an incompletely resected CN had disease progression after 37 months but at the time of last follow-up had had stable disease for 10 years. In addition, the authors reported 5 patients with disease recurrence occurring at a median of 67 months after surgery (range, 51-79 months after surgery), all of which occurred after complete surgical resection was performed. The observation period for the remaining 5 patients was short (median of 34 months [range, 5-44 months]). Extensive histologic and immunohistochemical workup did not identify any significant prognostic parameters. The MIB-1 proliferation index ranged from 0.8-11% (median of 4.6%), but was reported to be 46.8% in the malignant transformed tumor. All patients with disease recurrence responded well to different forms of focal radiation therapy (gamma knife radiosurgery in three patients and interstitial irradiation in one patient) and for one patient with a recently detected recurrence, gamma knife radiosurgery was planned. CONCLUSIONS: CNs appear to have a higher tendency to recur during long-term follow-up than previously reported, even after complete resection. Therefore, periodic neuroradiologic follow-up examinations should be considered mandatory in all patients, even after several years.

Adolescent↗

PubMed2004

Value and limits of immunohistochemistry in differential diagnosis of clear cell primary brain tumors.

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 in diameter) of well-defined OGs, CCEs, and CNs (n=10, respectively). Antibodies comprised anti-neuron specific nuclear protein (NEUN), anti-synaptophysin, anti-neuron-specific enolase, anti-microtubule-associated protein 2, anti-phosphorylated neurofilament protein, anti-non-phosphorylated neurofilament protein, anti-glial fibrillary acidic protein (GFAP), anti-S100 protein, anti-vimentin (VIM), and anti-epithelial membrane antigen (EMA). Among the panel of antibodies anti-NEUN, anti-VIM and anti-EMA proved most useful for differential diagnosis. Prominent (>90%) anti-NEUN immunolabeling of tumor cells clearly distinguished CNs from OGs and CCEs. Anti-VIM immunolabeling and a characteristic cytoplasmic dot-like anti-EMA immunoreactivity pattern of tumor cells were detectable only in OGs and CCEs. Furthermore, prominent anti-VIM immunoreactivity and anti-EMA cell membrane staining including ring-like staining pattern is characteristic for CCEs. Additionally, a widespread gliofibrillary and minigemistocytic cytoplasmic anti-GFAP immunostaining pattern is restricted to some OGs. Our data indicate that immunohistochemistry using anti-NEUN, anti-VIM, and anti-EMA on representative tumor specimens allows clear-cut distinction of CNs vs OGs and CCEs. Anti-VIM, anti-EMA, and anti-GFAP support differential diagnosis of OGs vs CCEs. Nevertheless, it is noted that due to focal expression of glial proteins in CNs and, conversely, of neuronal proteins in OGs and CCEs, immunohistochemistry is of limited value on small tumor specimens.

Biomarkers, Tumor↗

PubMed2002

Disease-associated prion protein in vessel walls.

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 variant Creutzfeldt-Jakob disease. Experimental studies have established the involvement of cells of the lymphoid and peripheral nervous system in the transport of prions to their target central nervous system tissue. To evaluate the role of vessel wall-associated mobile cells, we obtained formalin-fixed tissue blocks from various brain regions and/or basal arteries from sporadic, variant and iatrogenic Creutzfeldt-Jakob disease, and unselected control cases. We demonstrate disease-associated prion protein deposits in intracranial vessel walls, in sporadic and variant Creutzfeldt-Jakob disease by performing immunohistochemical staining and paraffin-embedded tissue blotting. Using double immunofluorescence, these deposits co-localize with HLA-DR and S-100 immunoreactive cells in the intima, which are components of the vascular-associated dendritic cell network, as well as with HLA-DR and CD-68 immunopositive macrophages of the intima and media. We conclude that mobile cells in vessel walls like dendritic and monocyte/macrophage lineage cells may be involved in spread of disease-associated prion protein and possibly also of infectivity.

Animals↗