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W Feiden

Publications and source records attributed to W Feiden.

At least 55 records · Page 3Linked to original sources
PubMed1998

Primary lymphoma of the heart: report of a case with histological diagnosis of the transvenously biopsied intracardiac tumor.

Primary cardiac lymphoma is an extremely rare disease and is associated with a high mortality. In most cases, lymphomatous involvement of the heart and/or pericardium occurs as a late manifestation of disseminated disease. Primary cardiac lymphoma is treatable when appropriately diagnosed. We report the case of an immunocompetent 69-year-old patient who presented with signs of dyspnea and a transmural mass infiltrating the apical section of both ventricles. Examination of the tissue obtained by transvenous biopsy revealed high-grade non-Hodgkin's lymphoma of B-cell lineage. The patient was treated successfully with CHOP chemotherapy. This case demonstrates that early diagnosis and intensive chemotherapy might contribute to a better prognosis for patients with malignant lymphoma of the heart.

Aged↗
PubMed1998

[Grading of astrocytomas and oligodendrogliomas].

The histologic determination of the degree of tissue anaplasia and grade of malignancy of gliomas is based upon qualitative histological features (nuclear pleomorphism, mitoses, endothelial proliferation, tumor necrosis). This grading approach is influenced by the subjective interpretation of the pathologist, especially concerning the weighting of criteria (scant, moderate, pronounced). An observer-independent approach seems to be feasible by abandoning the concept of parameter weighting in favor of an binary approach noting only the presence or absence of these structure parameters. This grading procedure is recognized in the revised WHO classification of brain tumors for common type astrocytomas (Ste. Anne-Mayo System, SAMS). Our results indicate that a similar approach is also suitable for grading purposes of oligodendrogliomas and mixed gliomas. Our recent investigations on glioma grading showed, both for astrocytomas and oligodendrogliomas, that a two-tiered grading scheme distinguishing only "low-grade" and "high grade" cases was prognostically relevant. For all glioma entities the onset of tumor angiogenesis with endothelial proliferation and contrast enhancement in CT and MRI seems to be the key criterion indicating irreversible tumor progression to the "high" malignancy grade.

Astrocytoma↗
PubMed1998

Demonstration of platinum microcoils in embolized blood vessels in-situ using a modified methyl methacrylate embedding method, and a special cutting and grinding technique.

With current paraffin embedding techniques it is not possible to demonstrate metal particles in vascular lumens. We used a modified methyl methacrylate embedding method for obtaining plastic blocks which were cut with a precision diamond saw, and subsequently ground and polished to preserve the interface of reactive tissue surrounding platinum microcoils in arteriovenous malformations. Artifact-free interfaces could be achieved by slow embedding under vacuum conditions, slow polymerization in a water bath, and very gentle cutting, grinding and polishing techniques. The method produces good preservation of tissue and cells directly adjacent to metal coils. Our method is useful for the histomorphological interpretation of vascular pathologies in which metal particles have been introduced.

Adult↗
PubMed1998

Case of the month: May 1997--a 31 year old woman with seizures, fatigue and attention deficits.

A 31-year-old woman with a five year history of seizures complained of worsening fatigue and attention deficits. At age 26, neuroradiological imaging studies had shown a small, non-enhancing hypodense lesion involving the left frontobasal and subcallosal region. Follow-up CT and MRI images showed that the lesion had not changed. A stereotactic biopsy showed a dysembryoplastic neuroepithelial tumor (DNT). The lesion was subtotally resected and the diagnosis of DNT was fully confirmed. However, the distinction between oligodendroglioma, ganglioglioma, focal dysplastic cerebral cortex, and DNT was only possible with knowledge of the clinical and neuroradiological data.

Adult↗
PubMed1997

[Meningioma. Classification and grading].

Meningiomas account for the most frequent primary intracranial neoplasms in adults. In 1993, the so-called atypical meningioma has additionally been introduced in the revised edition of the WHO Classification of Tumors of the Central Nervous System and should characterize meningiomas with an increased propensity to recur. Since the given qualitative histological criteria apply both to the "atypical" and anaplastic meningioma, mere histological grading appears somewhat critical. Therefore, additional parameters were tested for their contribution to meningioma grading: First of all, we succeeded in defining 3 meningioma "grades" by calculating corresponding 95% confidence intervals for the morphometrically assessed Ki-67 indices of 160 meningiomas in total, the validity of which was proved by comparison with the "recurrence"-free intervals. Histologically, atypical meningiomas were distinguished by a "syncytial", poorly structured growth pattern and macronucleoli. Only occasionally, nuclear pleomorphism, necroses and mitotic figures were found. Cytogenetics revealed, in 50% of the "atypical" and anaplastic meningiomas, partial loss of the short arm of one chromosome 1 (1p-). Histochemically, we could demonstrate, that the tissue non-specific type of alkaline phosphatase (ALPL), which is coded on chromosome 1p, is a convenient recurrence- and progression-associated marker enzyme for meningiomas with 1p-loss (loss of enzyme activity in 30/39 of intermediate and 8/8 anaplastic meningiomas). We favor to address the WHO "atypical" meningioma as meningioma of the intermediate type, since the attribute "atypical" in the context of histological diagnoses is highly susceptible to misinterpretations.

Adult↗
PubMed1997

Loss of alkaline phosphatase activity in meningiomas: a rapid histochemical technique indicating progression-associated deletion of a putative tumor suppressor gene on the distal part of the short arm of chromosome 1.

Apart from defined histomorphologic features, increased Ki-67 indices and various numeric and structural chromosome aberrations, meningiomas of the intermediate (WHO grade II, atypical meningioma) and anaplastic type (WHO grade III) are cytogenetically distinguished from common-type meningiomas (WHO grade I) by frequent loss of the distal part of the short arm of one chromosome 1 (1p-), which formerly proved to be an independent predictor of shorter recurrence-free intervals. Histochemically, loss of alkaline phosphatase activity (ALPL, liver/bone/kidney type, EC 3.1.3.1) was another frequent, specific finding in meningiomas with signs of dedifferentiation. In a prospective study including 66 meningiomas, all common-type meningiomas except one case (18/19) were reactive for ALPL, whereas 75% (30/39) of intermediate type and all anaplastic meningiomas (8/8) showed loss of enzyme activity in large areas of the tumor. Exclusively, the ALPL negative phenotype was associated with 1p loss (15/19). Our data suggest that ALPL, which is coded as a single copy gene on chromosome 1p36.1-p34, is a useful marker enzyme for the loss of a putative regulatory (tumor suppressor) gene on chromosome 1p, or that ALPL itself represents a new tumor suppressor gene homozygously inactivated in meningiomas.

Alkaline Phosphatase↗
PubMed1997

Histologic and morphometric grading of gliomas. A comparative survival analysis.

OBJECTIVE: A grading system based upon morphometrically assessed quantitative parameters (HOM system) was correlated with the results of classical histologic grading (St. Anne/Mayo system [SAMS], 1988, and World Health Organization classification, 1993). Validation was done by comparison with survival data. STUDY DESIGN: This retrospective study consisted of representative paraffin-embedded tissue sections of 139 adults who had been surgically treated for supratentorial common gliomas between 1988 and 1994. Histologic grading diagnoses were adapted to the latest standard. Computer-assisted image analysis of Ki-67 (MIB1)/ Feulgen-stained sections provided nuclear parameters appropriate to define homogeneous grades of malignancy by multivariate statistical analyses: average segment length of the minimum spanning trees (ASLMST) for the quantitation of tumor growth pattern; nuclear area percentage (NAP), reflecting cellularity; and volume-weighted mean nuclear volumes (vV) for estimating nuclear size and pleomorphism. RESULTS: Analysis of survival data yielded no statistically significant differences between astrocytomas and oligoastroacytomas (Lee-Desu test, alpha = 5%). Furthermore, only two prognostically different grades could be established, "low grade" and "high grade" gliomas, with the first representing SAMS grades 2 and 3 and the latter SAMS grade 4 (alpha = .1%). The same applied to HOM grades (alpha = .1%). Cox regression analysis of survival data demonstrated that histologic grading diagnoses and NAP tallied best with patients' outcome.

Adult↗
PubMed1996

Early proliferation enhancement by monosomy 10 and intratumor heterogeneity in malignant human gliomas as revealed by smear preparations from biopsies.

We performed simultaneous fluorescence in situ hybridization (FISH) with centromere-specific DNA probes for chromosomes 7 and 10 and Ki-67 proliferation labelling on smear preparations of 17 differentiated and anaplastic human astrocytomas and glioblastomas. In 15 of the 17 cases studied, Ki-67-positive clones differed from Ki-67-negative clones mainly by the loss of one copy of chromosome 10, either combined with or independent of trisomy 7. The findings suggest that monosomy 10 is an earlier event than generally supposed in the development of human gliomas and that it is directly related to cellular hyper-proliferation.

Astrocytoma↗
PubMed1996

[Dysembryoplastic neuroepithelial tumor (DNT). Pattern of neuroradiologic findings].

Dysembryoplastic neuroepithelial tumors (DNT) were first described as a new tumor entity by Daumas-Duport et al. in 1988 and were introduced into the revised WHO classification of brain tumors in 1993. The purpose of this study was to work out neuroradiological CT and MRT patterns of DNT. Five patients, aged 11-61 years (three female, two male) underwent complete presurgical neuroradiological exploration (5 CT, 4 MRT investigations, 2 angiography) because of brain tumor. Four cases complained of seizures and one of occipital-located headache. Total microsurgical excision was achieved in two cases. Two further lesions were resected subtotally after stereotactic biopsy diagnosis. In one case, stereotactic biopsy alone was carried out. All DNTs were localized cortically: two frontobasal medial in the gyrus rectus, two temporobasal in the gyrus occipitotemporalis lateralis and one infratentorial in the lobus caudalis cerebelli. They were sharply demarcated from the surrounding brain tissue. Cortical localization was better visualized by MRT, especially on coronal and sagittal images. CT scans showed a hypodense lesion, MRT a high-signal intensity in T2, low signal in T1 and in proton-weighted images a hyperintense rim with a slightly hyperintense small cyst. The multinodular tumor architecture was best seen in MRT. Two DNTs presented partial contrast enhancement, while three DNTs did not take up contrast. In two lesions there were focal calcifications. The infratentorial DNT was associated with a bony defect of the tabula interna into which the tumor expanded. Two angiographies showed no pathological tumor neovascularization. A hypodense sharply demarcated lesion with a multinodular pattern in MRT with cortical location and without space-occupying signs is, in combination with the clinical symptom of epileptic seizures, highly suggestive of DNT. As our results demonstrate, DNT can also occur in the infratentorial space.

Adolescent↗
PubMed1996

Data-driven approaches to decision making in automated tumor grading. An example of astrocytoma grading.

OBJECTIVE: To compare four data-driven approaches to automated tumor grading based on morphometric data. Apart from the statistical procedure of linear discriminant analysis, three other approaches from the field of neural computing were evaluated. STUDY DESIGN: The numerical basis of this study was computed tomography-guided, stereotactically obtained astrocytoma biopsies from 86 patients colored with a combination of Feulgen and immunhistochemical Ki-67 (MIB1) staining. In these biopsies the cell nuclei in four consecutive fields of vision were evaluated morphometrically and the following parameters determined: relative nuclei area, secant lengths of the minimal spanning trees and relative volume-weighted mean nuclear volumes of the proliferating nuclei. RESULTS: Based on the analysis of these morphometric features, the multivariate-generated HOM grading system provides the highest correct grading rates (> 90%), whereas the two widely employed qualitative histologic grading systems for astrocytomas yield correct grading rates of about 60%. For automated tumor grading all approaches yield similar grading results; however, back-propagation networks provide reliable results only following an extensive training phase, which requires the use of a supercomputer. All other neurocomputing models can be run on simple UNIX workstations (AT&T, U.S.A). CONCLUSION: In contrast to discriminant analysis, backpropagation and Kohonen networks, the newly developed neural network architecture model of self-editing nearest neighbor nets (SEN3) provides incremental learning; i.e., the training phase does not need to be restarted each time when there is further information to learn. Trained SEN3 networks can be considered ready-to-use knowledge bases and are appropriate to integrating further morphometric data in a dynamic process that enhances the diagnostic power of such a network.

Algorithms↗
PubMed1995

Rat monoclonal antibodies differentiating between the Epstein-Barr virus nuclear antigens 2A (EBNA2A) and 2B (EBNA2B).

Rat monoclonal antibodies were produced against the C-terminus of Epstein-Barr virus nuclear antigens 2A (EBNA2A) and 2B (EBNA2B) expressed as bacterial trpE fusion proteins. The initial screening was performed using a soluble bacterial extract containing the fusion proteins. Positive hybridomas were confirmed by immunofluorescence on SF158 (Spodoptera frugiperda) insect cells infected with recombinant baculovirus (Autographa californica nuclear polyhedrosis virus) and expressing the complete EBNA2A or EBNA2B genes. We selected a panel of antibodies which reacted either with both antigens or specifically with EBNA2A or with EBNA2B. The antibodies were extensively characterized using immunoprecipitation, Western blotting, epitope mapping on synthesized peptide segments of EBNA2A, immunocytology, and immunohistology on both cryostat sections and paraffin sections of AIDS-associated primary central nervous system lymphomas.

Animals↗
PubMed1995

Triple approach for diagnosis and grading of meningiomas: histology, morphometry of Ki-67/Feulgen stainings, and cytogenetics.

With regard to meningioma grading and the recently introduced "atypical" meningioma, we evaluated 160 cases retrospectively by conventional histology and image analysis. For that, the cell nuclei were stained with a Ki-67 (MIB1)/Feulgen-method on paraffin sections, thus enabling the assessment of both the Ki-67 proliferation index and nuclear morphometric features, such as tumour cell arrangement, nuclear pleomorphism, and cellularity. It could be demonstrated that the Ki-67 proliferation index is the most important criterion for distinguishing anaplastic meningiomas (WHO "grade" III) (mean Ki-67 index: 11%) from those of common type (WHO "grade" I) (mean Ki-67 index: 0.7%). The parameter for the "relative volume weighted mean nuclear volume" is another valuable morphometric feature. The "atypical" meningioma (WHO "grade" II) which should represent an intermediate category between common type and anaplastic meningiomas is characterized by a mean Ki-67 proliferation index of 2.1%. Common type meningiomas which comprise almost 50% of the cases of this series have a relapse rate of 9%. "Atypical" and anaplastic meningiomas recurred in 29% and 50%, respectively. Since the term "atypical" meningioma is confusing in the context of tumour grading, the term "intermediate type meningioma" is proposed. Furthermore, the results of cytogenetic analyses of 142 cases of this series were evaluated and compared with the meningioma grades. Thereby, 25 cases disclosed, independent of the typical loss of one chromosome 22, cytogenetic features assumed to be progression-associated, e.g., the gain or loss of different chromosomes and the deletion of the short arm of one chromosome 1 (hyperdiploidy, increased hypodiploidy, 1p-), when correlated to the histological and morphometric findings or the high relapse rate. For meningioma diagnosis and grading, a practical guideline is proposed based upon histology, morphometry (Ki-67), and cytogenetics.

Biomarkers, Tumor↗
PubMed1995

Gagel's granuloma (localized Langerhans cell histiocytosis) in the pituitary stalk.

A 46-year-old man with diabetes insipidus, hypothyroidism and hypocortisolism was found to have a tumor of the pituitary stalk. After transsphenoidal resection of the tumor substitution of cortisol and thyroxin was necessary. Pathological examination of the lesion revealed an extremely rare granulomatous infiltration classified as Gagel's granuloma (Langerhans' cell histiocytosis). Pre- and postoperative magnetic resonance imaging (MRI) studies, differential diagnosis and treatment of such lesions are presented.

Diabetes Insipidus↗
PubMed1995

Microsurgery of cerebral lesions under stereotactic conditions.

Microsurgical excision of cerebral lesions was carried out under CT-guided stereotactic conditions. For lesions located in critical cortical areas, cerebral teleangiography under stereotactic conditions provided the coordinates of the vascular elements related to the structures and adjacent to the lesion without X-ray distortion. Small size cortical and subcortical lesions were targeted using the stereotactic biopsy probe as a guide. In twenty-four patients stereotactic microsurgery was used for following lesions: 8 cavernomas, 8 metastases, 7 gliomas, and 1 tuberculoma. Unpredictable permanent neurological complications did not occur, but predicted transient impairment after surgery in functional territories was tolerated with the complete removal of the lesion. The advantages of microsurgery using stereotactic coordinates are: precise knowledge of the location of brain structures and exact targeting of intracerebral lesions, better evaluation of surgical risks, easy spatial orientation, and minimization of the surgical damage to the healthy brain tissue.

Adolescent↗
PubMed1995

[Intracerebral hemorrhage and multiple brain abscesses caused by Bacillus cereus within the scope of acute lymphatic leukemia].

Multiple hematogenic brain abscesses in immunosuppression are occasionally caused by rare and primary apathogenic causative agents. We report a first case of an isolated CNS infection by Bacillus cereus, which led to death from multiple brain abscesses and an intracerebral hemorrhage, probably caused by the infection, within 4 days. The underlying disease leading to immunosuppression was acute lymphatic leukemia in complete remission. In spite of antibiotic therapy the chemotherapy-induced neutropenia enabled unhindered spreading of the necrotizing infection, which was verified by histological analysis. The production of potent toxins such as hemolysin and cerelolysin by B. cereus leads to rapid and fulminant tissue destruction usually involving the walls of blood vessels.

Adult↗
PubMed1995

Automated grading of astrocytomas based on histomorphometric analysis of Ki-67 and Feulgen stained paraffin sections. Classification results of neuronal networks and discriminant analysis.

In stereotactically obtained astrocytoma biopsies, four morphometric nuclear parameters were determined with the use of an image analysis system. A special Ki-67 (MIB1)/Feulgen stain made it possible to quantify the essential characteristics of gliomas of the astrocytoma/glioblastoma group: growth pattern, cellularity, proliferation tendency and nucleus pleomorphism. A grading scale based on a cluster analysis resembling the WHO-scheme, which is suitable for automated astrocytoma grading, was developed. Large back propagation neural networks were used and their results compared with those of a classical multivariate discriminant classification analysis. It is possible to show that the neural network technology is superior to the statistical approach for automated astrocytoma grading. Based on the results of our study we believe neural network technology to be useful for tumour grading problems. The presented approach can be generalized for the automated grading of other tumour entities.

Astrocytoma↗