Karl Donath

[Diagnosis and ultrastructure of the tubular carcinoma of salivary gland ducts. Epithelial-myoepithelial carcinoma of the intercalated ducts].

The carcinoma of the ducts of the salivary glands, according to light- and electronmicroscopic analyses of 8 cases, corresponds to an epithelial-myoepithelial carcinoma of the intercalated ducts. The intercalated duct carcinoma is a rare and special type of salivary gland carcinoma (it represents about 0.5% of all epithelial tumors of the salivary gland; its highest incidence is in the 7th decade; it occurs more frequently in women). The tumors consist of two cell types, with organoid structures. There are on the one hand dark cells with few organelles forming the inner layer of the tubules (similar to the intercalated ducts), and on the other clear cells rich in organelles and glycogen that form the outer layer with myoepithelial differentiation (myofilaments, endoplasmatic reticulum, pinocytosis vesicles, glycogen- and lipofuscin granulas). Up to now the tumors have been described under different synonyms (tubular-solid adenoma, cystic adenoma, adenomyoepithelioma) and when the myoepithelial cells clearly predominated the tumors were called glycogen-rich (myoepithelial or clear cell) adenomas. In the differential diagnosis the intercalated duct carcinomas must be distinguished from acinic cell tumors, cylindromas (adenoid cystic carcinomas) and from mucoepidermoid tumors. The pluripotence of the intercalated ducts arises from their development from the salivary gland. The different morphologic pictures of the tumors histogenetically derived from the intercalated ducts may be explained by the various differentiation of the epithelial cells and by the myoepithelial cells of the intercalated ducts. Das tubuläre Speichelgangcarcinom stellt auf Grund einer licht- und elektronenmikroskopischen Analyse von 8 Fällen ein epithelial-myoepitheliales Schaltstückcarcinom dar. Die Schaltstückcarcinome sind eine seltene Sonderform des Speicheldrüsencarcinoms (etwa 0,5% aller epithelialen Speicheldrüsentumoren; Altersgipfel im 7. Lebensjahrzehnt; häufigeres Vorkommen beim weiblichen Geschlecht). Die Tumoren sind aus zwei Zellformen organoid aufgebaut: dunkel, organellenarme Zellen als innere Zellschicht der tubulären Formationen (analog den Schaltstückepithelien) und helle, organellen- und glykogenreiche äußere Zellschicht mit myoepithelialer Differenzierung (Myofilamente, endoplasmatisches Reticulum, Pinocytosebläschen, Glykogen- und Lipofuscingranula). Die Tumoren sind bisher unter verschiedenen Synonymen (tubulär-solides Adenom, cystisches Adenom, Adeno-Myoepitheliom), beim Überwiegen der myoepithelialen hellen Zellformen auch als glykogenreiches (myoepitheliales oder hellzelliges) Adenom beschrieben worden. Differentialdiagnostisch müssen die Schaltstückcarcinome von den Acinuszelltumoren, Cylindromen (adenoid-cystischen Carcinomen) und Mucoepidermoidtumoren abgegrenzt werden. Die Pluripotenz der Schaltstücke ergibt sich aus der Entwicklung der Speicheldrüsen. Die unterschiedliche Struktur der histogenetisch aus den Schaltstücken abzuleitenden Tumoren (Schaltstückcarcinome, Cylindrome, pleomorphe Adenome) läßt sich durch die verschiedene Differenzierung sowohl der Schaltstückepithelien als auch Myoepithelien erklären.

Histologic subclassification of the cystadenolymphoma of the parotid gland

Cystadenolymphomas (CAL) of the parotid gland are variable in their epithelial differentiation and the ratio of the epithelial tumor component to lymphoid stroma. Two hundred and seventy five cases of CAL from the files of the Salivary Glands Register of the Institute of Pathology, University of Hamburg (1965–1979) were analysed. Their pathogenesis from parenchyma included in regional lymph nodes is discussed. The following Subclassification was established. 1. Depending on to the ratio of epithelial tumor component to lymphoid stroma, three subtypes were distinguished. Subtype 1, “typical CAL” with an epithelial tumor component of 50%, amounted to 77% of all cases of CAL studied. Oncocytic differentiation and focal metaplasia to goblet cells or squamous epithelium was also found. 13.5% of CAL were classified as subtype 2, “stroma-poor CAL” with an epithelial tumor component of 70 to 80%). The tumor structure was similar to that of an oncocytoma in places. Two per cent of the CAL were in subtype 3, “stroma-rich CAL” with an epithelial tumor component of only 20 to 30%. Subtype 3 was found solely in men. The average age at presentation (61 years) was slightly lower than that of all the cases studied (65 years). 2. In 7.5% of the cases large areas of squamous cell metaplasia and regressive changes was found within a CAL. These cases were classified as subtype 4 (“metaplastic CAL”). The average age was 67 years. The case histories showed that 20% of these metaplastic CAL had previously been irradiated. 3. Bilateral CAL was found in 7.5% of the cases. In 4% multifocal CAL occurred in the parotid gland unilaterally. Recurrences were observed in 2% of all CAL. 4. Carcinoma in CAL is rare (we found two cases in our own material). In 50% of all cases reported radiotherapy was mentioned in the case histories. 5. Malignant tumors coincident with CAL were recorded in 3% of the cases. 6. The lymphoid stroma showed reaction patterns similar to those of the regional lymph nodes. These included granulomatous changes (foreign body granuloma with cholesterol deposits, tuberculosis) and tumor metastases. In the neighborhood of oncocytic tumor epithelium focal accumulations of plasma cells forming IgA and IgG were found. Depending on to the ratio of epithelial tumor component to lymphoid stroma, three subtypes were distinguished. Subtype 1, “typical CAL” with an epithelial tumor component of 50%, amounted to 77% of all cases of CAL studied. Oncocytic differentiation and focal metaplasia to goblet cells or squamous epithelium was also found. 13.5% of CAL were classified as subtype 2, “stroma-poor CAL” with an epithelial tumor component of 70 to 80%). The tumor structure was similar to that of an oncocytoma in places. Two per cent of the CAL were in subtype 3, “stroma-rich CAL” with an epithelial tumor component of only 20 to 30%. Subtype 3 was found solely in men. The average age at presentation (61 years) was slightly lower than that of all the cases studied (65 years). In 7.5% of the cases large areas of squamous cell metaplasia and regressive changes was found within a CAL. These cases were classified as subtype 4 (“metaplastic CAL”). The average age was 67 years. The case histories showed that 20% of these metaplastic CAL had previously been irradiated. Bilateral CAL was found in 7.5% of the cases. In 4% multifocal CAL occurred in the parotid gland unilaterally. Recurrences were observed in 2% of all CAL. Carcinoma in CAL is rare (we found two cases in our own material). In 50% of all cases reported radiotherapy was mentioned in the case histories. Malignant tumors coincident with CAL were recorded in 3% of the cases. The lymphoid stroma showed reaction patterns similar to those of the regional lymph nodes. These included granulomatous changes (foreign body granuloma with cholesterol deposits, tuberculosis) and tumor metastases. In the neighborhood of oncocytic tumor epithelium focal accumulations of plasma cells forming IgA and IgG were found. Metaplasia to squamous epithelium is believed to be caused by circulatory disturbances, irradiation, and other noxae. In the differential diagnosis of the stroma-poor subtype 2, oncocytoma and cystic sialadenoma must be excluded, and in the differential diagnosis of subtype 4 (the metaplastic CAL), sebaceous adenoma, mucepidermoid tumor, squamous cell carcinoma, lymphoepithelioma, and other non-tumorous lesions of the parotid gland (lymphoepithelial cysts, myoepithelial parotitis) must be ruled out. Our findings suggest that CAL develops from parenchyma included in parotid lymph nodes with the oncocytic ductal epithelium representing the neoplastic component.

Ultrastructural studies of the parotid glands in sialadenosis

30 parotid biopsies of patients with sialadenosis-a symmetrical, painless, non-inflammatory, recurrent parotid swelling-were studied by electron microscopy. The patients suffered from different diseases, such as diabetes mellitus, liver diseases, hypertension and other affections. Parotid biopsies from 25 patients with slight parotitis or with oral cancer were used as controls. Morphometric studies reveal that the parotid swelling is caused by an enlargement of acinar cells. In controls the average diameters of the acinar cells are 30 to 40 μ. In sialadenosis the diameters are enlarged to 50 to 70 μ, in some cases to a maximum of 100 μ. Histologically the cytoplasm of the enlarged acinar cells shows either a granular pattern due to a numerical increase in secretory granules or a vacuolar transformation. Ultrastructurally the vacuolar transformed acinar cells also contain an increased number of granules with less electron density than the surrounding cytoplasm. Three types of sialadenosis can be distinguished with regard to the electron density of the acinar granules: a) a dark granular type, b) a pale granular type and c) a mixed granular type. The mixed granular type probably develops from the dark granular form. Alterations leading to the destruction of the myoepithelial cells were observed in all three types of sialadenosis with minimal changes in the dark granular type. Degenerative alterations of the autonomic nervous system are evident in all three groups with most pronounced changes in the pale granular type of sialadenosis. The ultrastructural alterations are interpreted as a disturbance of secretion, probably primarily caused by the degeneration of the autonomic nervous system. The alteration of the autonomic nervous system is suggested to be the common pathogenetic principle in all types of human sialadenosis occurring with different basic diseases. The enlargement of the acinar cells is the result of an intracellular disturbance in the secretory process due to the preceding defect of the autonomous nerval structures. 30 Parotisbiopsien von Patienten mit Sialadenose (doppelseitige schmerzlose, nichtentzündliche Parotisschwellung) wurden elektronenmikroskopisch untersucht. Bei den Patienten hatten unterschiedliche Grundkrankheiten (z.B. Diabetes mellitus, Lebererkrankungen, Hypertonie u.a.) vorgelegen. Als Kontrollgruppe wurden Parotisbiopsien von 25 Patienten mit geringer Parotitis oder einem Mundhöhlencarcinom untersucht. Die morphometrischen Untersuchungen ergaben, daß die Parotisschwellung auf einer Vergrößerung der Drüsenendstücke beruht. Die mittleren Acinusdurchmesser liegen in der Kontrollgruppe bei 30 bis 40 μ und sind bei den Sialadenosen auf 50 bis 70 μ, in einigen Fällen maximal bis auf 100 μ. vergrößert. Pathohistologisch läßt sich im Cytoplasma der vergrößerten Acinuszellen entweder eine Anreicherung von Granula oder eine feinvesikuläre Aufhellung beobachten. Elektronenmikroskopisch enthalten die Acinuszellen mit vesiculärem Cytoplasma ebenfalls Granula, jedoch von geringerer elektronenoptischer Dichte als das umliegende Cytoplasma. Nach der elektronenoptischen Dichte der Sekretgranula lassen sich drei Formen der Sialadenose unterscheiden: a) eine dunkle granuläre Form, b) eine helle granuläre Form und c) eine gemischte granuläre Form. Es wird angenommen, daß sich die gemischte granuläre Form aus der dunklen granulären Form entwickelt. Alterationen der Myoepithelzellen treten bei allen drei Formen der Sialadenose auf, am geringsten bei der dunklen granulären Form. Degenerative Veränderungen des autonomen Nervensystem lassen sich bei allen drei Formen beobachten, am stärksten bei der hellen granulären Form der Sialadenose. Die ultrastrukturellen Veränderungen sprechen für eine Sekretionsstörung, die wahrscheinlich durch eine Degeneration des autonomen Nervensystems ausgelöst wird. Die primäre Alteration des autonomen Nervensystem wird als das gemeinsame pathogenetische Prinzip aller Formen der menschlichen Sialadenose bei den verschiedenen Grundkrankheiten angesehen. Die Vergrößerung der Acinuszellen ist Ausdruck einer intracellulären Sekretionsstörung als Folge der vorausgehenden Schädigung der autonomen Innervation.

Biology of Metastasizing Ameloblastoma

The present report of a malignant metastasizing ameloblastoma and a critical review of literature was undertaken in an attempt to better understand the biological potential and behavior of this rare tumor and thus to facilitate its clinical management. Most of the 26 patients with a proven malignant ameloblastoma including the present case had developed multiple recurrences. The lung was the most frequent metastatic site (88%) followed by regional lymph nodes (27%). Furthermore metastases were observed in some cases in the bone, brain, kidney, small intestine and liver. The interval between diagnosis of tumor and manifestation of metastases was long with a median of 11.1 years. The average survival time was 13.1 years. By contrast, the interval between diagnosis of metastatic disease and death was relatively short (median: 2.6 years). The histologic and cytologic pattern of malignant ameloblastoma and of its metastases was not significantly different from that of non-metastatic ameloblastoma. Because of the lack of morphological criteria of malignancy the biological behavior of ameloblastomas cannot be predicted. It is difficult to be certain which factors are important in the delayed induction of metastases. It is suspected that ameloblastomas possess an inherent low grade malignancy which is stimulated by multiple recurrences. It is further assumed that the metastatic tumor cells have a slow growth rate resulting in late clinical manifestation of metastases. When lung metastases occur we recommend their surgical removal in order to prolong live expectancy or even to obtain a curative effect.

Multiple tumours of the salivary glands--terminology and nomenclature.

Multiple tumours of the salivary glands are very rare and their combinations according to histological classification of the tumours, localisation and origin (origin in independent topographical areas or in the same tissue) are diverse. The following two categories can be distinguished: common occurrence of multiple salivary gland tumours with identical histology, or with different histology. In either group the tumours can be unilateral or bilateral, synchronous or metachronous. The most common multiple tumours with an identical histology are Warthin tumours and pleomorphic adenomas. Bilateral occurrence has been observed especially in oncocytomas, acinic cell carcinomas and basal cell adenomas. In the group of multiple tumours with differing histology, Warthin tumours and pleomorphic adenomas show a number of combinations with other adenomas or carcinomas of the salivary glands. Notable also is the simultaneous occurrence of salivary gland tumours with other oral tumours or extraglandular tumours, especially thyroid carcinomas and breast carcinomas. Multiple salivary gland tumours must be distinguished by nomenclature from tumours with biphasic differentiation and hybrid tumours. Tumours with biphasic differentiation are defined as regular, recurring mixtures of two cellular components in the same tumour and have a corresponding term in the tumour classification. Hybrid tumours are very rare and are composed of two different tumour entities within the same topographical area. Each of the tumour entities conforms with an exactly defined tumour category.

Hybrid tumours of salivary glands. Definition and classification of five rare cases.

Hybrid tumours are very rare tumour entities which are composed of two different tumour entities, each of which conforms with an exactly defined tumour category. The tumour entities of a hybrid tumour are not separated but have an identical origin within the same topographical area. In contrast, biphasically differentiated tumours are a mixture of two cellular patterns with a corresponding term in the tumour classification. Examples of a biphasic differentiation are: basaloid-squamous carcinoma, adeno-squamous carcinoma or sarcomatoid carcinoma, and epithelial-myoepithelial carcinoma, mucoepidermoid carcinoma or adenoid cystic carcinoma. Hybrid tumours must also be distinguished from the multiple occurrence of salivary gland tumours which can develop syn- or metachronously. In the tissue samples of more than 6600 salivary gland tumours covered by the Salivary Gland Register (Institute of Pathology, University of Hamburg, Germany) only 5 cases of hybrid tumours were recorded between 1965 and 1994. This means less than 0.1% of all registered tumours. Case 1 was a very rare example of a hybrid adenoma with differentiation as a basal cell adenoma and a canalicular adenoma of the parotid gland. The similar cellular origin of both types of adenoma may be an explanation for its development in a hybrid adenoma. Case 2 is a hybrid tumour with a composition of basal cell adenoma and a glandular type of adenoid cystic carcinoma. In both types of tumours the two cell types (duct-lining cells and modified myoepithelial cells) have a similar histogenetic origin. Therefore, the development of the both cell types in a hybrid tumour with two trends of differentiation is possible. Case 3 represents a hybrid adenoma as a mixture of a Warthin tumour and a sebaceous adenoma. Although inclusions of sebaceous cells are observed in Warthin tumours, this hybrid tumour shows a composition of two different epithelial structures in a varied mixture. Case 4 is a very rare and unique hybrid carcinoma with two absolutely different components: acinic cell carcinoma and salivary duct carcinoma. The poor prognosis of this hybrid carcinoma is determined by the salivary duct carcinoma. Case 5 represents a hybrid carcinoma whose two components have a similar histogenetical basis: epithelial-myoepithelial carcinoma and a glandular type of adenoid cystic carcinoma. Both carcinomas are composed of variable proportions of ductlining cells and myoepithelial cells.

The histopathology of different foreign-body reactions in oral soft tissue and bone tissue

Foreign bodies may be endogenous or exogenous and provoke chronic inflammation of the foreignbody type. The reaction provides a mechanism for elimination of the foreign body and the reaction pattern depends on the kind of tissue involved. In soft tissues there is cellular inflammation and fibrous encapsulation with macrophages. In bone, during the healing period, biomechanical factors determine whether a fibrous encapsulation or a bony covering develops demarcating the foreign material. The particular characteristics of the foreign-body reaction in bone explain the success of dental and orthopaedic implants.

Lipomatous pleomorphic adenoma of the parotid gland. Classification of lipomatous tissue in salivary glands.

Lipomatous pleomorphic adenoma is an unusual subtype with a lipomatous stromal component of more than 90% of the tumour tissue. This special type of pleomorphic adenoma must be distinguished from other types of lipomatous tumours or non-tumourous lipomatosis of the salivary glands. Until now only two cases of lipomatous pleomorphic adenoma have been reported in the literature. We report of a 36-year old woman who developed a well circumscribed nodule measuring 3.5 x 2.5 x 2 cm in the right parotid gland. The cut surface was grey-yellowish. Histologically, more than 90% of the tumour tissue was fatty tissue with univacuolar adipocytes. The pleomorphic epithelial elements were duct-like cells forming small lumina and spindle-shaped myoepithelial cell with surrounding mucoid stroma. Components of pleomorphic adenoma were intermingled with mature adipose tissue which was more concentrated in the central portion of the adenoma. Some compressed epithelial cords in the adipose tissue formed a septa-like pattern. The differential diagnosis to other lipomatous tumours (lipoadenoma, lipoma) and to non-tumourous interstitial lipomatosis as well as the possible pathogenesis as metaplastic change or epithelial-mesenchymal transdifferentiation are discussed.

Die Morphologie der Speicheldrüsenerkrankungen

The human salivary glands represent a functional system with manifold responsibilities and interactions to the organism. The major and minor salivary glands show a common construction schedule consisting of an acinar functional system for the production of an enzyme- and mucin-containing primary saliva and a ductal functional system with manifold secretory, resorptive and regulatory responsibilities for the transport and the definitive composition of the saliva. The cyclic AMP and calcium iones localized in the glandular acini have an exceptional importance for the course of the secretory process. The neurohormonal control of the salivary secretion results by adrenergic and cholinergic transmitter substances. Moreover the secretory process shows a daily cycle combined with morphological alterations of the glandular cells (so called circadian structures). The fluid secretion of the salivary duct system (the output of sodium-, potassium- and chlorine-iones) represents an active energy-consumed transport process which will be regulated by several factors (autonomic nervous system, quantity of perfusion, hydrostatic pressure in the blood capillaries, transepithelial active transport by ATP-consumed pump systems). The striated ducts are the functional most important sector of the duct system for a rapid fluid- and electrolyte excretion. The terminal axons of the postganglionic sympathic and parasympathic neurits are characterized by spindle-shaped enlargements (varicosities) which contain neurosecretory granules. In the region of the acinar and intercalated duct cells a direct synaptic contact exists for the stimulation transmission, in the course of which the terminal axon contacts immediately with the effector cell by penetration of the basement membrane. The salivary glands form a part of the stabil tissues with reversible postmitotic cells in regard of the tissue regeneration. Under pathological conditions (inflammations, impediment of secretion fluid, radiation effects etc.) metaplasias and proliferations of the duct system arise with development of indifferent duct formations analogous to the type of an embryonal salivary gland. The terminal zone between intercalated and striated ducts represents an indifferent zone with large regeneratory potency. A special behaviour shows the myoepithelial cells which are developed as well to the outside of primitive embryonic duct buds as differentiated intercalated and striated ducts. Morphologically three types of diseases can be classified in the salivary glands: sialadenosis, sialadenitis and tumours.(ABSTRACT TRUNCATED AT 400 WORDS)SummaryThe human salivary glands represent a functional system with manifold responsibilities and interactions to the organism. The major and minor salivary glands show a common construction schedule consisting of an acinar functional system for the production of an enzyme- and mucin-containing primary saliva and a ductal functional system with manifold secretory, resorptive and regulatory responsibilities for the transport and the definitive composition of the saliva. The cyclic AMP and calcium iones localized in the glandular acini have an exceptional importance for the course of the secretory process. The neurohormonal control of the salivary secretion results by adrenergic and cholinergic transmitter substances. Moreover the secretory process shows a daily cycle combined with morphological alterations of the glandular cells (so called circadian structures). The fluid secretion of the salivary duct system (the output of sodium-, potassium- and chlorine-iones) represents an active energy-consumed transport process which will be regulated by several factors (autonomic nervous system, quantity of perfusion, hydrostatic pressure in the blood capillaries, trans-epithelial active transport by ATP-consumed pump systems). The striated ducts are the functional most important sector of the duct system for a rapid fluid- and electrolyte excretion. The terminal axons of the postganglionic sympathic and parasympathic neurits are characterized by spindle-shaped enlargements (varicosities) which contain neurosecretory granules. In the region of the acinar and intercalated duct cells a direct synaptic contact exists for the stimulation transmission, in the course of which the terminal axon contacts immediately with the effector cell by penetration of the basement membrane. The salivary glands form a part of the stabil tissues with reversible postmitotic cells in regard of the tissue regeneration. Under pathological conditions (inflammations, impediment of secretion fluid, radiation effects etc.) metaplasias and proliferations of the duct system arise with development of indifferent duct formations analogous to the type of an embryonal salivary gland. The terminal zone between intercalated and striated ducts represents an indifferent zone with large regeneratory potency. A special behaviour shows the myoepithelial cells which are developed as well to the outside of primitive embryonic duct buds as differentiated intercalated and striated ducts. Morphologically three types of diseases can be classified in the salivary glands: sialadenosis, sialadenitis and tumours.The sialadenosis is a “non-inflammatory disease of the salivary gland parenchyma, due to disorders in glandular metabolism and glandular secretion and usually associated with recurrent, painless bilateral enlargement of salivary glands, especially of the parotid”. Pathohistologically it is found an enlargement of the acini with filling of the cytoplasm by secretory granules. Ultrastructurally the alterations of the acinar cells correspond to a secretory stage characterized by a prolongated storage phase of the secretory granules as soon as an inhibition of protein synthesis and comparable to the findings after symphatolysis or food deprivation. The other ultrastructural changes (progressive transformations of myoepithelial cells, alterations of the vegetative nervous system) are reasons to believe that the sialadenosis represents a primary vegetative neuropathy with resulting disturbance of the secretory cycle.In sialadenitis the following main types can be distinguished: 1. Bacterial sialadenitis, 2. Viral sialadenitis (Parotitis epidemica, Cytomegaly, Coxsackievirus infections), 3. Radiation sialadenitis, 4. Electrolyt sialadenitis, 5. Küttners tumour of the submandibular gland and 6. Immunosialadenitis. The Küttners tumor represents a progressive inflammation of the salivary ducts with distinct alterations of the duct epithelias, development of lymph follicles, atrophy of parenchyma and formation of a sclerosis or cirrhosis of the salivary glands. The inflammatory process proceeding in four section phases is formed particularly by immunopathological reactions. Within the scope of the immuno defense the salivary glands are a special secretory immunological system. The synthesis of the secretory component takes place in the striated ducts, the excretion in the duct lumens together with the immunoglobuline A. Experimentally an allergic sialadenitis of immuno complex type and an autoallergic sialadenitis can be produced. The importance of the “Myoepithelial sialadenitis” (Sjögrens syndrome) as an auto-immuno disease of the salivary glands based on morphological, serological and clinical findings. The morphological substrate is characterized by an extensive destruction of the glandular tissue with formation of myoepithelial islands. In the course of the disease alterations of the cell islands result with destruction of the cells of the intercalated ducts, proliferation of the myoepithelial cells, desintegration of the basement membrane and lymphocytic cell infiltration as soon as hyalinization. The inflammatory process must be distinguished to the epitheloid cellular sialadenitis in Heerfordts syndrome differential diagnostically. In Sjögrens syndrome several observations are published about the development of malignant immunoblastic lymphomas in the last time.In the salivary gland tumours four main categories — corresponding to the international classification of the W.H.O. — can be classified: adenomas, acinic cell tumours, mucoepidermoid tumours and carcinomas. Under 2 600 surgical specimens examinated in the salivary gland register from 1965 to 1974 1 067 tumour cases (41%) were found. 929 of these cases (87%) were epithelial tumours, 89 (8%) non-epithelial tumours (hemangiomas etc.) and 49 (5%) metastases or periglandular tumours. 71,5% of the epithelial tumours could be classified as benign (51,5% pleomorphic adenomas, 20% monomorphic adenomas), 28,5% as malignant (2,5% acinic cell tumours, 6% mucoepidermoid tumours, 20% carcinomas). For the carcinomas the following distribution of frequency was registrated: 6,5% adenoid cystic carcinomas, 2% other adenocarcinomas, 2% epidermoid carcinomas, 4% carcinomas in pleomorphic adenomas and 5,5% other carcinomas (salivary duct carcinomas, clear cell carcinomas, anaplastic carcinomas).In regard of the cyto- and histogenesis a classification in two tumour groups is possible, namely in monomorphic and pleomorphic tumours. Monomorphic tumours are basal cell adenomas, onkocytomas, papillary cystadenolymphomas (Warthins tumours), sebaceous gland tumours, clear cell tumours and acinic cell tumours. The morphological, especially ultrastructural characteristics are demonstrated. A subclassification of the pleomorphic adenomas is proposed which considers not only the differentiation of the epithelial cells (salivary duct and myoepithelial cells, epidermoid cells, basal cells etc.) but also the quality (mucoid, chondroid, hyaline, fibrous, fascicular) and quantity of the stroma. The classic type of the pleomorphic adenoma (type 1=30%) shows a colored epithelial cell picture and a mucoid stroma (quote to the complete tumour about 30–50%). The type 2 (55%) is stroma-rich (80% of the complete tumour) with predominant mucoid stroma structure (37,5%). The types 3 and 4 are stromapoor (20–30% quote of stroma) and particularly differentiated more monomorphic. As prototype of the tumour cells poorly differentiated duct and myoepithelial cells are considered (75–90% of all cell types). The ultrastructural signs are characterized. In regard of the malignancy three tumour types must be considered isolated: 1. Benign pleomorphic adenomas with metastases, 2. Primary malignant pleomorphic adenomas and 3. Carcinomas in pleomorphic adenomas. The characteristics of the other tumours with pleomorphic differentiation are presented. The localization of the tumours constitutes an important indication for the prognosis (higher percentage of malignant tumours in the submandibular gland than in the parotid gland). Observations of double or multiple tumours of the salivary glands are interesting for the pathogenesis and etiology. Experimentally salivary gland tumours can be produced by chemical cancerogens (cyclophosphamide, dimethylbenzanthracene), oncogenic viruses (Polyoma-virus, adeno-virus etc.) and radiation effects.In infancy the diseases of the salivary glands show another spectrum as well in regard of the inflammations as the tumours. The acquirement of criterias for the prognosis and therapy, the analysis of interactions between salivary glands and immuno system as soon as the clarification of possible correlations between salivary glands, pancreas and endocrine system are main points of interest on the prospective research.ZusammenfassungDie Mundspeicheldrüsen des Menschen stellen ein funktionelles System mit vielfältigen Aufgaben und Wechselwirkungen zum Organismus dar. Die großen und kleinen Speicheldrüsen weisen ein gemeinsames Bauprinzip auf, welches aus einem acinären Funktionssystem zur Bildung eines enzym- und mucinhaltigen Primärspeichels und einem ductalen Funktionssystem mit vielfältigen sekretorischen, resorptiven und regulatorischen Aufgaben für den Transport und die endgültige Zusammensetzung des Speichels besteht. Das in den Drüsenacini lokalisierte cyclische AMP und Calcium-Ionen besitzen für den Ablauf des Sekretionsprozesses eine besondere Bedeutung. Die neurohormonale Steuerung der Speichelsekretion erfolgt durch adrenergische und cholinergische Überträgersubstanzen. Außerdem zeigt der Sekretionsprozeß eine Tagesrhythmik, die mit morphologischen Strukturveränderungen (sog. Circadianstrukturen) der Drüsenzellen einhergeht. Die Flüssigkeitssekretion im Speichelgangsystem (Abgabe von Natrium-, Kalium- und Chlor-Ionen) stellt einen aktiven, energieverbrauchenden Transportvorgang dar, welcher von mehreren Faktoren (autonomes

Zur Pathogenese der Parotisatrophie nach experimenteller Gangunterbindung

In 24 Wistar-rats the right Stenon duct was tied off and the gland tissue studied by light- and electron microscopy at different time intervals after duct ligation (6 hours to a maximum of 6 months). The left parotid gland was used for comparsion. The earliest and most pronounced structural changes were found at the highly differentiated acini of the gland (fragmentation and vesicular transformation of the endoplasmatic reticulum, focal cytoplasm necroses, osmiophilic inclusions, mucoid transformations of the secretory granula). The dissolution process going hand in hand with the necroses of the acini cells comes to an end on day 10 of the experiment. Damages to the duct system appears later. Corresponding to the degree of differentiation the destruction of the interlobular ducts is more severe and appears earlier than that of the intercalated ducts. After 4–6 months the structural change in the duct system leads to the formation of indifferent ducts, as in an embryonic parotid gland. The myoepithelial cells remain intact and prove to be a separate cell system. The reactions of the connective tissue in the salivary gland together with the parenchymal atrophy result in abacterial sclerosis of the salivary-gland tissue. The transformation of the parotid gland after experimental duct ligation corresponds to diseases of the human salivary gland (chronic sialadenitis, sialolithiasis, radiation injury) in its course and in the location and extent of pathologic structural changes. The tissue reaction of the salivary glands to noxious influences of different etiology is obviously limited. Only the immunologically induced alterations of the gland show specifical patterns of histological reactions. Bei 24 weiblichen Wistar-Ratten wurde der rechte Parotisausführungsgang unterbunden und das Drüsengewebe in verschiedenen zeitlichen Abständen nach der Gangligatur (6 Std bis maximal 6 Monate) licht- und elektronenmikroskopisch untersucht. Die linke Parotis wurde als Vergleichsobjekt verwendet. Die frühesten und stärksten Veränderungen finden sich an den hochdifferenzierten Drüsenacini (Fragmentation und vesiculäre Transformation des endoplasmatischen Reticulums, fokale Cytoplasmanekrosen, osmiophile Einschlüsse, mucoide Transformation der Sekretgranula). Der mit Acinuszellnekrosen einhergehende Auflösungsprozeß ist mit dem 10. Versuchstag weitgehend abgeschlossen. Die Schädigungen des Gangsystems treten zeitlich später auf. Entsprechend dem Differenzierungsgrad sind die Destruktionen der Streifenstücke stärker und auch zeitlich früher als die der Schaltstücke. Die Strukturumwandlung des Gangsystems führt nach 4–6 Versuchsmonaten zu indifferenten Gangformationen vom Typus einer embryonalen Speicheldrüse. Die Myoepithelzellen bleiben intakt und erweisen sich als eigenständiges Zellsystem. Die am Speicheldrüsenmesenchym ablaufenden Reaktionen führen zusammen mit der Parenchymatrophie zu einer abakteriellen Speicheldrüsensklerose. Die Umgestaltung der Parotis nach experimenteller Gangunterbindung entspricht sowohl im zeitlichen Ablauf als auch der Lokalisation und dem Stärkegrad Befunden, wie sie bei Spontanerkrankungen menschlicher Speicheldrüsen (chronische Sialadenitis, Speichelsteinen, Strahlenschäden) zu beobachten sind. Die Gewebsreaktion des Speicheldrüsengewebes gegenüber Noxen unterschiedlicher Ätiologie ist offensichtlich begrenzt. Lediglich immunologisch ausgelöste Prozesse zeigen spezielle Reaktionsmuster.