Dankwart Stiller

Cellular composition of the so-called dermatofibroma (Histiocytoma cutis)

9 typical cases of dermatofibroma or histiocytoma cutis resp. were studied by the aid of histochemical, enzyme histochemical and electron microscopical methods to examine the cellular composition of these lesions. The results suggest an anabolic and katabolic function of cells. Electron microscopically a broad spectrum of patterns of mesenchymal cells was found. Besides defined fibroblast-like and histiocyte-like elements a cell type was detected which was characterized by particular traits, as irregularnuclear outline, abundant rough endoplasmic reticulum, free ribosomes, bundles of filaments with single dense zones, micropinocytotic vesicles and a basement membrane-like material on the outer cell surface. This cell type constitutes the majority of cells in dermatofibroma or histiocytoma cutis resp. In some cells an arrangement of filament bundles resembling that in smooth muscle could be seen. By reason of these findings a certain resemblance to the so-called myofibroblasts can be stated. The variegation of the morphological picture suggests a multipotent precursor cell; the possibility of an origin from pericytes is discussed. An Hand 9 typischer Fälle von Dermatofibrom bzw. Histiocytoma cutis wurde mittels histochemischer, enzymhistochemischer und elektronenmikroskopischer Methoden die celluläre Zusammensetzung untersucht. Dabei waren Hinweise auf anabolische und katabolische Eigenschaften der Zellen zu erheben. Elektronenmikroskopisch ergab sich ein breites Spektrum mesenchymaler Zellformen. Neben definierten fibroblasten- und histiocytenähnlichen Zellelementen fand sich eine Zellart, die das morphologische Bild zahlenmäßig beherrschte und die durch besondere Merkmale, wie unregelmäßige Kernformen, reichlich rauhes endoplasmatisches Reticulum, freie Ribosomen, Filamentbündel mit einzelnen Verdichtungsbezirken, Mikropinocytosevesikel und ein basalmembranähnliches Material an der ZellaußenScite charakterisiert war. Gelegentlich konnte eine Anordnung der Faserbündel wie in der glatten Muskulatur nachgewiesen werden. Auf Grund dieser Befunde ist eine gewisse Ähnlichkeit zu sogenannten Myofibroblasten festzustellen. Die Vielgestaltigkeit des morphologischen Bildes weist auf eine multipotente Vorläuferzelle hin; die Möglichkeit, daß es sich dabei um Pericyten handelt, wird diskutiert.

Cellular features in desmoid fibromatosis and well-differentiated fibrosarcomas

In the study presented here the ultrastructural cellular features of three desmoids and four well-differentiated fibrosarcomas were compared. Electron microscopically, the tumors were almost identical relative to qualitative traits. The majority of cells corresponded to fibroblast-like cells with certain morphological variations. Especially cells with characteristics of myofibroblasts must be emphasized, whereas cells with an organelle composition of classical fibroblasts were surprisingly seldom. Considering the relations of cells to each other and to vessels the prevailing origin of tumor cells from preexisting fibroblasts is suggested.

Ultrastructural cytology of human osteosarcoma cells.

The cytology of 6 osteosarcomas was examined by electron microscopy. In keeping with the varied pattern of osteosarcomas seen by light microscopy several types of tumor cells could be differentiated: osteoblast-like, fibroblast-like, chondroblast-like, osteoclast-like and histiocyte-like cells. Moreover, atypical malignant mesenchymal cells and vascular spaces were present. The individual cytoplasmic organelles are not considered to be specific to particular types of cell as seen from the discussion of the significance of rough endoplasmic reticulum, microfilaments and lysosomes. Only examination of the composite pattern of subcellular organelles allows the differentiation of certain cell types. All tumor cells visible in osteosarcomas are considered as modifications of a transformed common progenitor cell. Because of the variegated cytological picture a multipotent mesenchymal cell rather than an osteoblastic cell is assumed to be the ancestor cell.

Malignant fibrous histiocytoma of bone

Malignant fibrous histiocytoma (MFH) of bone is a well-defined tumor by light microscopy but no agreement has been achieved concerning its histogenesis. We present the light and electron microscopic findings of four cases of MFH of bone. In case 1 multiple bone tumors were observed and in case 4 the tumor developed after irradiation. It was our aim to document the cytological variability and to arrange the findings in a histogenetic concept of primary intraosseous MFH. We observed some undifferentiated cells but mainly histiocyte- and fibroblast-like cells including intermediate forms, and several types of giant cells. We should emphasize the fact that there were also some large cells with a light microscopic resemblance to rhabdomyoblasts and with electron microscopic characteristics of myoblastic differentiation. From the ultrastructural point of view, therefore, MFHs seem to derive from a primitive mesenchymal stem cell rather than from the ordinary histiocyte. It is suggested that osteosarcoma and MFH of bone may have a common progenitor cell but it is important to make a clear clinico-pathological distinction between the tumors because of differing biological behavior.

Morphogenesis of Intracytoplasmic Dense (Inclusion) Bodies in a Recurring Digital Fibrous Tumor of Childhood

This study presents the results of light-microscopic, histoehemical, and electronmicroscopic investigations of dense (inclusion) bodies in a recurring digital fibrous tumor of childhood. At ultrastructural level it was possible to observe several stages of development correlated with changes of ergastoplasmic reticulum. The viral nature of these bodies was refuted and the conclusion was drawn that their formation is associated with a disturbed intracellular metabolism. The defective intracellular transport of collagen precursors followed by abnormal deposition of collagenous proteins, which are also to some extent abnormally aggregated, could be of special importance. In der vorliegenden Arbeit werden lichtmikroskopische, histochemische und elektronenmikroskopische Untersuchungsergebnisse an sogenannten Einschlußkörperchen bei der von Reye beschriebenen Säuglingsfibromatose der Finger mitgeteilt. Es wurden elektronenmikroskopisch verschiedene Entwicklungsstadien dieser Gebilde in enger Beziehung zu Veränderungen des ergastoplasmatischen Retikulums beobachtet. Die Befunde legen die Folgerung nahe, daß es sich bei diesen Strukturen nicht um Viren oder ihre Produkte, sondern um die abnorme Ablagerung von Proteinen im Rahmen eines gestörten intrazellulären Transportes von Kollagenvorstufen handelt.

Cellular differentiations and structural characteristics in nasopharyngeal angiofibromas

An electron-microscopic study of 9 nasopharyngeal angiofibromas was performed in order to elucidate the ultrastructural characteristics. Stromal fibroblasts and proliferating cells of the microvasculature were found. The stromal fibroblasts were subdivided into 3 different groups: (1) “classical” fibroblasts, (2) fibroblasts with histiocytelike features, and (3) fibroblasts with myoid features. By proliferation the cells of the capillary vessels change into stromal cells. A particular pattern of nuclei and dense intranuclear granules is only found in stromal fibroblasts. Consequently fibroblasts as well as cells of the microvasculature contribute to the pool of tumor cells.

Ultrastructural cytology of regenerating tendon--an experimental study.

Cellular differentiations in regenerating tendon tissue of rats and guinea pigs were examined by the aid of the electron microscope. Fibroblasts with certain variations were found as basic cell types. Corresponding to the organelle composition classical fibroblasts, fibroblasts with histiocyte-like features and fibroblasts with myoide differentiations (comparable to the so-called myofibroblasts) were identified. Furthermore, proliferating capillaries with remarkable pericytic activities among other things producing fibroblast-like features must be mentioned. This fact led to the conclusion, that a part of fibroblasts in the proliferating connective tissue during tendon repair may derive from pericytes. Our ultrastructural investigations showed proof of the great plasticity of fibroblasts which function as stem cells in connective tissue regeneration.

The subcutaneous fascial analogue of myositis proliferans

Two cases of the so-called fascial analogue of myositis proliferans were investigated by histological and electron microscopic methods. It was found that the structure of the fascial variant corresponds almost completely to the true myositis proliferans localized within the musculature. The electron microscopic observations show a preponderantly histiocytic differentiation of the cells and strongly activated proliferating capillaries, and exclude a myogenic origin of the characteristic ganglion-like giant cells. Ultrastructurally a traumatic genesis appears possibly, the cells of the lesion could derive from multipotent cells of the microvasculature. The relations to myositis ossificans and fasciitis nodularis are discussed. 2 Fälle einer in der Faszie lokalisierten Variante der Myositis proliferans wurden histologisch und elektronenmikroskopisch untersucht. Dabei zeigt sich eine weitgehende Ähnlichkeit zur echten, intramuskulär lokalisierten Myositis proliferans. Die elektronenmikroskopischen Befunde ergeben eine überwiegend histiozytäre Differenzierung der Zellen und stark aktivierte proliferierende Kapillaren und schließen einen myogenen Ursprung der charakteristischen Ganglienzell-ähnlichen Riesenzellen aus. Auf Grund der Feinstruktur erscheint eine traumatische Genese möglich, wobei die Zellen ihren Ausgang von multipotenten Gefäßwandzellen nehmen könnten. Die Beziehungen zur Myositis ossificans und Faszitis nodularis werden diskutiert.

Jugular body tumors: Hyperplasias or true neoplasms?

Problems of classification of certain growth processes were discussed using jugular body tumors to find out cytological criteria for characterizing growth traits. For this purpose light microscopical (9 cases), electron microscopical (6 cases) and enzyme histochemical investigations (3 cases) were performed. For comparison 4 carotid body tumors were examined. We are inclined to assume a neoplastic nature. An explanation as hyperplastic proliferation is refuted because a remarkable cellular variation in size and form, only sparse nerve fibers and lacking synaptic contacts, because submicroscopical features and because the clinical picture and course of the disease. It is pointed to the origin of the tumor cells from rudimentary endocrine-like cells occurring in the glomus jugulare-tympanicum in analogy to other neoplasias. The clinical symptoms, the course and the pathologic anatomical pattern suggest an interpretation of jugular body tumors as potential malignant growths. An Hand von Paragangliomen des Mittelohres (jugular body tumors) werden Probleme der Klassifikation von Wachstumsprozessen erörtert. Im Vordergrund stand die biologische Einordnung dieser Tumoren. Dabei wurden zytologische Kriterien mittels lichtmikroskopischer (9 Fälle), elektronenmikroskopischer (6 Fälle) und enzymhistochemischer Methoden (3 Fälle) erarbeitet. Zum Vergleich wurden 4 Karotiskörpertumoren herangezogen. Als Ursache dieser Gewächse wird eine hyperplastische Proliferation abgelehnt. Die Annahme der neoplastischen Natur ergibt sich aus der zellulären Form- und Größenvariation, der Spärlichkeit von Nervenfasern und dem Fehlen von Synapsen, ferner aus submikroskopischen Befunden sowie aus dem klinischen Bild und dem Verlauf der Erkrankung. Der Ursprung der Tumorzellen wird auf rudimentäre, endokrinähnliche Zellen zurückgeführt. Damit besteht eine Analogie zu anderen Neoplasien. Die klinischen Symptome, der Verlauf und das pathologisch-anatomische Bild legen eine Interpretation der Paragangliome des Mittelohres als potentiell maligne Gewächse nahe.

Structural patterns and histological behaviour of experimental sarcomas: I. General considerations, histology and histochemistry

Methylcholanthrene-induced rat sarcomas were used as a model for the examination of morphological and cytological differentiations in tumours of the connective tissue. Particular attention was paid to the question how far these sarcomas are comparable to human connective tissue tumours. The histological examination yields a broad spectrum of mesenchymal differentiations ranging from undifferentiated anaplastic sarcomas over less differentiated fibrosarcomas and malignant fibrous histocytomas to well-differentiated fibrosarcomas, myosarcomas and haemangiopericytomas. It is worth mentioning that different histological structures can be encountered with one and the same tumour.