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  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Cancer Genetics and Cytogenetics 66 (1993), S. 93-99 
    ISSN: 0165-4608
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0022-4731
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 366 (1975), S. 287-304 
    ISSN: 1432-2307
    Keywords: Carcinoma of the Prostate ; Endocrine Therapy ; Radiation Therapy ; Ultrastructnre
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Elektronenmikroskopische Untersuchungen an Prostatacarcinomen relativ kurze Zeit nach Orchiektomie, Telekobaltbestrahlung und medikamentöser Hormontherapie zeigen degenerative Veränderungen an den Tumorzellen und dem fibromuskulären Organstroma. Dies sind an den Tumorzellkernen folgende Alterationen: Heterochromasie, bizarre Umwandlungsformen, Segmentierungen, Invaginationen (‚'Kerneinschlüsse”) und Erweiterung des perinukleären Spaltes. Das Cytoplasma der Tumorzellen ist vakuolär degeneriert. An der Grenze zum Stroma sind Plasmalemm und Basalmembran der Tumorzellen ausgedehnt zerstört. Das bindegewebige Stroma zeigt eine Zellproliferation sowie eine degenerative Umwandlung der Kollagenfasern bis hin zur Hyalinisierung. Die glatte Muskulatur ist dissoziiert, die Muskelzellen sind fragmentiert und vakuolär degeneriert. Die Blutgefäße zeigen eine Endothelschwellung und eine Wandverdickung. Es bleibt offen, in welchem Maße die einzelnen Therapieschritte am gesamten Behandlungseffekt beteiligt sind. Die beschriebenen morphologischen Veränderungen gehen über die nach alleiniger Orchiektomie zu beobachtende Regression jedoch beträchtlich hinaus und sind z.T. kennzeichnend für strahlenbedingte Schädigungen. Der Grad der morphologischen Veränderungen ist allerdings nicht einheitlich. Das Auftreten intakter Tumorzellen neben vollständig degenerierten Zellen ist nicht ungewöhnlich. Dabei handelt es sich um wenig differenzierte Tumorzellen. Ob diese „embryonalen” Zellformen therapieresistent sind bzw. bleiben und ob sich aus ihnen ein Tumorrezidiv entwickeln kann, wird diskutiert.
    Notes: Summary Carcinomas of the prostate treated by orchiectomy, 60Co-radiation, and hormonal drugs a relatively short time prior to the time of biopsy were studied with the electron microscope. The following degenerative changes of tumor cells and fibromuscular stroma were found: The nuclei of the tumor cells were intensely heterochromatic, irregularly shaped, and the perinuclear rim dilated; large atypical sizes, multiple segmentations and “nuclear invaginations” were observed. The tumor cell cytoplasm showed vacuolar degeneration, and the limiting membranes of the tumor cells were extensively destroyed. Remarkable changes were also found in the fibromuscular stroma: There was a proliferation of collagenous fibers as well as degenerative transformations ending in hyalinization. The smooth muscle cells were dissociated and fragmented, sometimes showing vacuolar degeneration of the cytoplasm. The endothelium of the blood vessels was swollen, and the vessel walls were thickened. In spite of these radiation-induced lesions it remains undecided as to what degree the other therapeutic measures take part in the total therapeutic effects as seen in the ultrastructural findings. However, these regressive changes are much more pronounced than those seen after orchiectomy alone and partly resemble the findings which are characteristic of radiation induced structural lesions. The morphological changes are not uniform throughout the tumor. It is not unusual to find intact tumor cells next to totally degenerated cells. They represent poorly differentiated tumor cells. It is discussed whether these “embryonic” tumor cell types are and remain resistant to treatment and if a tumor recurrance may originate in them later on.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 361 (1973), S. 241-256 
    ISSN: 1432-2307
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 20 confirmed human prostatic carcinomas of various histological types were studied by electron microscopy. As a result of the ultrastructural findings it was possible to define characteristic cell types which are normally present in prostatic carcinomas irrespective of their histological differentiation. As these cell types are frequently situated side by side, the prostatic carcinoma acquires a characteristic variegated appearance. Three main cell types can be distinguished. 1. A cell with a pale, euchromatic, round nucleus, very prominent nucleolus, and a narrow layer of bright cytoplasm with few organelles. This cell shows no secretory activity and has to be classified as a poorly differentiated or embryonic cell. It may be assumed that these cells have a high proliferative activity. 2. A cell with dark, pleomorphic, heterochromatic nucleus and a broad layer of dark cytoplasm containing numerous organelles. This cell type is apparently functionally stimulated and active. The disproportionate increase and arrangement of the organelles, however, makes it morphologically atypical: These alterations seem to result from an irregular process of enzyme synthesis and secretion. 3. A vacuolated cell: this cell has a dark, pyknotic nucleus and a broad layer of subtotally vacuolated cytoplasm. Probably it refers to a nonfunctional, hypersecretory and degenerative tumour cell. Transitional cell forms are not unusual. Sometimes carcinoma cells are visible in tumourous glands, and are so highly developed and well differentiated that the ultrastructural findings by themselves give no answer in the question of malignancy. Basal cells were seen in five of the carcinomas investigated, mainly in tumours with cribriform or solid patterns. The cytoplasm of these cells shows few organelles. Bundles of cytoplasmatic filaments are often present. It is uncertain whether these cells are of myoepithelial type. The knowledge of the described cell variants will be of clinicopathological importance if therapeutic effects on prostatic carcinoma are estimated cytomorphologically at the ultrastructural level.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-2307
    Keywords: Localized fibrous tumour of the pleura ; Benign mesothelioma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Five localized fibrous tumours of the pleura (benign mesothelioma) were studied ultrastructurally in order to elucidate their histogenesis. The histological subtypes of this benign fibrous lesion of the visceral pleura, i.e. the cellular, the collagenous, and the hyaline, were separately analysed. The tumours are composed of undifferentiated mesenchymal cells, intermediate and differentiated fibroblasts as well as collagenous interstitial tissue. The varying distribution of these cell elements account for the various histological subtypes. Morphological similarities between the mesenchymal tumour cells and the superficial mesothelial cells, which are always separated from the true tumour tissue by an intact basement membrane, were not observed. The different cellular elements can be regarded as parts of a continuous spectrum of cytodifferentiation, in which the mature fibroblasts are derived via intermediate forms from the undifferentiated cells. It is concluded that the localized fibrous tumours of the pleura arise from immature mesenchymal stem cells, which seems to be normally found in the submesothelial layer of the visceral pleura.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 380 (1978), S. 237-259 
    ISSN: 1432-2307
    Keywords: Xanthofibrogranulomatous lesion ; Inflammatory pseudotumor ; Sclerosing lesion of adipose tissue ; Retroperitoneal granuloma ; Fibroxanthomatous pseudosarcoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases are described of an extensive sclerosing lesion involving the retroperitoneum, mesentery, mediastinum and epicardium which is referred as Xanthofibrogranulomatosis. The term was chosen on histological criteria: granulomatous infiltration of chronic inflammatory cells without necrosis, proliferation of spindle-shaped, lipid-laden histiocytes, aggregation of xanthomatous cells and increased production of reticulin and collagenous fibers. Furthermore the name suggests that the lesion tends to be generalized although it does not represent a true neoplasm. In nearly all cases the changes are localized in the retroperitoneal adipose tissue extending to the renal hilus and enveloping the aorta and kidneys; other organs such as adrenals and pancreas are also often surrounded. The frequent cardiac manifestations (14 of 22 cases) with sclerosis of the epicardial fat especially in the right atrioventricular region are conspicous. Moreover involvement of organs may be found, e.g. the lungs or the posterior lobe of the pituitary gland in our cases. Generally the spread of the process shows a striking relation to large blood vessels. However, the distribution lacks uniformity. The characteristic localization and histology allows the distinction of Xanthofibrogranulomatosis from other well known disorders such as Ormond's, retroperitoneal fibrosis, panniculitis (Weber-Christian disease) and histiocytosis X (Hand-Schüller-Christian). The etiology and pathogenesis of Xanthofibrogranulomatosis are uncertain. Perhaps an autoimmune mechanism involving the fat cell membrane may play a part in the genesis of this chronic inflammatory sclerosing process. As long as no rational specific therapy exists, we must interpret the xanthofibrogranulomatous lesion as a slowly but irreversibly progressing disease which is clinically comparable with a malignant tumor.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 223 (1979), S. 437-439 
    ISSN: 1434-4726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The intravagal paraganglioma has its origin from paraganglionic, not chromaffinic receptor-cells, which are to be found within the ganglion nodosum (vagal body) itself or in its neighbourhood. In a casuistic report, the clinical picture of this tumor is described. The problems of the surgical treatment, when removing the tumor, are discussed. By means of light- and electron microscopy the histologic picture and the ultrastructural findings are presented. Observations on these tumors — as published in the literature — are compared with our case and discussed.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of cancer research and clinical oncology 96 (1980), S. 131-156 
    ISSN: 1432-1335
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of cancer research and clinical oncology 85 (1976), S. 287-297 
    ISSN: 1432-1335
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Hämangiopericytome der Meningen sind selten. Es wird über drei derartige Tumoren mit einem jeweils über 10 Jahre währenden Beobachtungszeitraum berichtet. Primär erfolgte die Klassifizierung in allen Fällen als Meningeom (1mal gefäßreich, 2mal angioblastisch). Erst nach z.T. mehrfachen Rezidiven sowie extracranieller Metastasierung in zwei Fällen wurden die Diagnosen revidiert und die Tumoren als Hämangiopericytom aufgefaßt. Morphologisch zeigen „angioblastisches Meningeom“ und „Hämangiopericytom der Meningen“ auffällige Gemeinsamkeiten. Das fundamentale Baumuster beruht auf der blastomatösen Vermehrung capillärer Blutgefäße mit normaler Endothelauskleidung, extracapillär proliferierter mesenchymaler Zellen vom Typ der Pericyten und einem intercellulären Netzwerk reticulärer Fasern. Die erhobenen licht- und elektronenmikroskopischen Befunde zeigen nicht die typischen Merkmale eines Meningeoms. Da zudem Klinik und Wachstumsverhalten von „angioblastischem Meningeom“ und „Hämangiopericytom der Meningen“ vergleichbar sind, erscheint es gerechtfertigt, diese Tumoren als einheitliche Geschwulstform mit gemeinsamer Histogenese anzusehen. Wegen der bekanntermaßen hohen Rezidiv- und Metastasierungsrate des Hämangiopericytoms einerseits — im Gegensatz zu der Gutartigkeit der üblichen Meningeome andererseits — halten wir es für sinnvoll, diese meningealen Tumoren einheitlich als „Hämangiopericytom der Meningen“ zu bezeichnen, um hinsichtlich des therapeutischen Vorgehens und prognostischer Aussagen die Besonderheit dieser meningealen Tumorform hervorzuheben.
    Notes: Summary Hemangiopericytomas of the meninges are rare tumors. Three tumors of this type with a course over more than 10 years each are reported. All three tumors were primary diagnosed as meningiomas (one: vascular, two angioblastic). The diagnosis was changed to hemangiopericytoma only then when recurrences and extracranial metastases had occurred. Morphologically, “angioblastic meningioma” and “hemangiopericytoma of the meninges” show striking common features. The principal pattern bases on the blastomatous increase of capillary blood vessels lined by a normal endothelium, extracapillary proliferation of pericyte-like mesenchymal cells and an intercellular network of reticulin fibres. Light- and electron microsopic findings do not demonstrate the characteristics of a meningioma. Furthermore, clinical data and growth pattern of “angioblastic meningioma” and “hemangiopericytoma of the meninges” are well comparable. Therefore, it seems to be justified to interpret these tumors as a tumor entity with identical histogenesis. It is well known that hemangiopericytomas frequently recur and metastasise. On the other hand, meningiomas are usually benign. For those reasons we suggest that these tumors should be uniformly classified as “hemangiopericytoma of the meninges” in order to stress the significance of these particular tumors of the meninges regarding their treatment and behaviour.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of cancer research and clinical oncology 86 (1976), S. 55-68 
    ISSN: 1432-1335
    Keywords: Rhabdomyosarcoma ; Rhabdomyoblast ; Cellular Differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der vorliegenden Untersuchung werden die cytomorphologischen Merkmale eines embryonalen Rhabdomyosarkoms des Nasenrachenraumes bei einem 10 jährigen Jungen aufgezeigt. Aufgrund der Ultrastruktur lassen sich im Tumor 4 Zelltypen darstellen: 1. Undifferenzierte mesenchymale Tumorzellen mit großem, euchromatischem Zellkern und schmalem, organellenarmem Cytoplasma; 2. undifferenzierte Tumorzellen mit einem Netzwerk von Intermediärfilamenten (Durchmesser etwa 100 Å) im breiten Cytoplasma; 3. unreife Rhabdomyoblasten mit zunehmender Entwicklung spezifische Myofilamente (Myosin: 180–210 Å, Actin: 68–80 Å Durchmesser); 4. reife Rhabdomyoblasten mit Myofibrillen in sarkomerischer Gliederung (Sarkomerlänge: 1,8 μ). Die starken Glykogenablagerungen in einigen cytoplasmareichen Tumorzellen werden als Zeichen eines Degenerationsprozesses gedeutet. Die cellulären Entwicklungsstadien des embryonalen Rhabdomyosarkoms sind identisch mit dem Ablauf der Embryogenese sowie der Regeneration normaler quergestreifter Muskulatur. Daher bieten sich für die Entstehung des embryonalen Rhabdomyosarkoms zwei Denkmodelle an: 1. Entstehung des Tumors aus einer undifferenzierten mesenchymalen Tumorstammzelle und 2. Atypische Regeneration nach Schädigung der quergestreiften Muskulatur mit Übergang in ein autonomes Tumorwachstum. Die zweite Hypothese ist jedoch wenig wahrscheinlich, da bis heute weder morphologisch noch experimentell eine derartige Tumorentstehung nachgewiesen werden konnte und zudem ätiologisch gesicherte Faktoren zur Induktion von Rhabdomyosarkomen beim Menschen fehlen.
    Notes: Summary An embryonal rhabdomyosarcoma of the nasopharynx of a 10 year old boy is analysed with light and electron microscopy. With regard to cell shape and cytoplasmic features the following four tumour cell types could be distinguished: 1. Undifferentiated mesenchymal cells with a big loosely packed nucleus and a small cytoplasmic rim with only few cell organelles; 2. Undifferentiated tumour cells with a broad cytoplasmic body which contains a dense network of nonspecific intermediate filaments with a diameter of about 100 Å; 3. Immature rhabdomyoblasts with randomly orientated specific myofilaments; 4. Fully differentiated rhabdomyoblasts with well developed myofibrils often showing a sarcomeric pattern. Glycogen deposits which were seen in great masses in many tumour cells were regarded to result from degenerative processes within the tumour. The cellular stages in the development of rhabdomyoblasts are basically identical to those known from the embryogenesis and regeneration of striated muscle. From these observations the two following developmental pathways are suggested: 1. Origin of the tumour from an undifferentiated mesenchymal cell; 2. Atypical regeneration of striated muscle which terminates in malignant progressive tumour growth. At present, the body of information about rhabdomyosarcomas supports the assumption of an origin from immature mesenchymal cells. Nevertheless, the second theory cannot be totally excluded.
    Type of Medium: Electronic Resource
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