Ultrastruktur und Pathogenese der myoepithelialen Sialadenitis: �ber das Vorkommen von Myoepithelzellen bei der benignen lymphoepithelialen L�sion

Distribution of intermediate filaments and actin microfilaments in parotid autoimmune sialoadenitis of Sjögren syndrome

In order to study the importance of myoepithelial cells in the formation of parotid epi-myoepithelial islands of the autoimmune sialoadenitis in Sjögren's syndrome, the distribution of cytoskeletal elements has been investigated by electron and immunofluorescence microscopy. Antibodies to intermediate filament proteins--prekeratins, desmin and vimentin--were used as well as a 'DNase I/anti-DNase I' immunohistochemical procedure to detect actin microfilaments for characterization of myoepithelial cells compared to the other types of parotid epithelial cells. Two types of prekeratin antibodies were raised. One of these reacted preferentially with myoepithelial cells. The same type of antiserum also showed a bright fluorescence in cells located peripherally in the epi-myoepithelial islands. These island cells, however, exhibited only a very low actin microfilament content and were thus not ordinary myoepithelial cells. The other type of prekeratin antibodies reacted with all types of parotid epithelia, except acinar secretory epithelium. They also stained all island epithelial cells, but the reactivity was less in cell regions with pronounced lymphocyte infiltration. The heterogeneity between the island epithelial cells, immunohistochemically as well as ultrastructurally, indicates different stages of island formation. Interepithelial lymphocytes showed less vimentin and actin filament content in comparison with lymphoid cells outside the islands. Conclusively, typical epi-myoepithelial islands are composed of metaplastic epithelial cells of intercalated duct origin and invaded lymphoid cells, and ordinary myoepithelial cells are lacking.

Involvement of Fas/Fas ligand in the induction of apoptosis in chronic sialadenitis of minor salivary glands including Sjögren's syndrome

The role of apoptosis and contribution of Fas/FasL systems in the pathogenesis of Sjogren's syndrome (SS) are still controversial. With serial sections, we explored apoptosis assessed by the dUTP nick end labeling (TUNEL) method and expression of Fas and FasL by immunohistochemistry, and compared their distribution in minor salivary gland (MSG) of SS and sialolithiasis (SIL) patient tissues. Fas and FasL were co-localized in ductular and acinar cells of SS and SIL TUNEL+ cells co-distributed with the Fas and FasL expressing cells in ductular and acinar cells of SS in the vicinity of lymphocytic infiltration, while not in those of SIL Moreover, to morphologically confirm apoptosis, we identified TUNEL-positive(+) cells in the MSGs of SS at the ultra structural level by applying an inversion method to paraffin-embedded sections stained by TUNEL method. Surprisingly, these cells did not show characteristic apoptotic figures although TUNEL products were deposited on the hyperchromatin of acinar and ductular cells. On the other hand, acinar and ductular cells of SIL included clusters of TUNEL+ apoptotic bodies as did those cells by phagocytosis or having fallen into the ductular lumen. These findings suggest that Fas and FasL expressed in ducts and acini of chronic sialadenitis in SS patients induce apoptosis, possibily in an autocrine and/or paracrine manner.

Pathology of the salivary glands: the contribution of electron microscopy

Electron microscopy has a limited role in the diagnosis of primary salivary gland tumors, although it can be helpful in metastatic lesions of possible salivary gland origin. The diversity of subtypes in salivary gland tumors, as well as the range of histomorphology within any one subtype, is unparalleled in any other human tumor. This and their relative infrequency causes diagnostic problems for pathologists. Ultrastructural techniques have been of major importance in determining the inter-relationship of these tumors for classification purposes, revealing the subtle variations in common cellular differentiation pathways, determining the organization of tumor cells, and displaying the importance of extracellular matrix materials in establishing diagnostic criteria for each of the many subtypes. Electron microscopy has also been valuable in non-neoplastic salivary gland disease and has an increasing role in experimental studies involving tissue from human and animal salivary parenchyma.

Immunohistochemical analyses of autoimmune sialadenitis in man

The immunoreactivity pattern for different monoclonal antibodies to cytokeratins and to vimentin in epimyoepithelial islands typical for glands of patients with Sjögren's syndrome has been compared with that of normal parotid gland tissue. Two types of epithelial island cells were observed: one had an intermediate filament protein pattern similar to that of ordinary duct epithelial cells of normal parotid gland. The other had an intermediate filament protein pattern typical of myoepithelial and/or basal duct cells in normal glands. Thus, we conclude that the islands are composed of a mixed population of gland cells on the basis of their content of cytokeratins or of cytokeratins and vimentin. These cells might originate from pluripotential reserve cells or from ordinary duct, myoepithelial and/or basal duct cells which may have undergone metaplasia.

Characterization of epimyoepithelial islands in benign lymphoepithelial lesions of major salivary gland: an immunohistochemical and ultrastructural study

Knowledge of the processes leading to the development of epimyoepithelial islands bears on histogenetic and morphogentic processes in salivary gland tumors. Immunohistochemical and ultrastructural investigations of the cellular composition of epimyoepithelial islands were carried out on three examples of benign lymphoepithelial lesions with varying histologic features. The monoclonal anti-keratin antibody 312C8-1, which specifically decorates myoepithelial cells of the normal salivary gland, also stains the myoepithelial cells surrounding residual acini and intercalated ducts in benign lymphoepithelial lesions and the cell population of epimyoepithelial islands, with the exception of persisting luminal epithelial cells. Ultrastructurally, the myoepithelial cells of involuting acini and ducts and the modified myoepithelial cells of epimyoepithelial islands, identified in both locations by the monoclonal antibody 312C8-1, show an increasing complement of tonofilament bundles. In addition, persisting lumens (often distended with lymphocytes) and definite luminal epithelial cells can be seen in electron micrographs of some epimyoepithelial islands. The designation for this characteristic epithelial feature of benign lymphoepithelial lesions is therefore appropriate.

Light and ultrastructural features of lymphoepithelial lesions of the salivary glands in Mikulicz's disease

This investigation deals with the histogenesis of the so-called 'epimyoepithelial islands' in Mikulicz's disease of the major salivary glands and is based on light and electron microscopic study in six patients. The 'epimyoepithelial islands' represent collapsed acini prior to their complete involution and disappearance, the intraductal cellular proliferation, stratification and differentiation into luminal and peripheral myoepithelial cells with partial and complete obliteration of their lumina and finally, cord-like proliferation and formation of nests of residual pluripotential cells showing squamous metaplasia and occasional myoepithelial cell differentiation. A pink, homogeneous and hyaline material on light microscopic examination is multilayered and extracellular and is in close association with the basal lamina when viewed with electron microscope.

Epimyoepithelial' islands in lymphoepithelial lesions. An immunocytochemical study

A panel of antibodies has been used in an immunoenzyme study in an attempt to characterize the cell types found in the 'epimyoepithelial' islands of lymphoepithelial lesions. Myoepithelial cells, which can be specifically stained with an anti-smooth muscle antibody were not found. The majority of cells stained with anti-prekeratin, suggesting a duct cell differentiation. A subpopulation of duct cells stainable with a monoclonal antikeratin (16a), previously described as occupying a basal location in normal salivary gland ducts, was clearly demonstrated. It is suggested that these cells may be important in the epithelial proliferation in these islands. The hyaline material within and surrounding the epithelial islands was positive for type IV collagen and therefore consists of basement membrane material.

Multinucleate giant cells in sublabial salivary gland tissue in Sjögren's syndrome. A diagnostic pitfall

The presence of multinucleate giant cells in the sublabial salivary gland tissue in Sjögren's syndrome is an unusual phenomenon which can give rise to differential diagnostic problems. We found in 4 cases of 55 patients with Sjögren's syndrome multinucleate giant cells. In 2 of these 4 patients epimyoepithelial islands were also present. The combination of both multinucleate giant cells as epimyoepithelial islands can mimic the histological picture of a non- caseating granulomatous disease. To discriminate between an epimyoepithelial island and an epithelioid granuloma the immunoperoxidase technique with antibodies directed against muramidase appeared an useful tool. The epithelioid cells contain muramidase whereas the cells in the epimyoepithelial island do not contain this enzyme. Thus, multinucleate giant cells are a rare phenomenon in Sjögren's syndrome, therefore restricting its diagnostic significance. When they occur in Sjögren's syndrome staining for muramidase can be of help to avoid a false positive diagnosis of diseases in which non- caseating granulomatous inflammation occur, such as in sarcoidosis.

Immunohistochemical and ultrastructural demonstration of keratin in epi-myoepithelial islands of autoimmune sialadenitis in man

Immunohistochemistry of salivary gland suggested that keratin is a specific marker of duct-epithelial cells and myosin for myoepithelial cells. Epi-myoepithelial islands found in some autoimmune sialadenitis, such as Sjögren's syndrome, were mainly composed of keratin-positive cells. Keratin filaments, with bundles and desmosome-attachments were invariably found in epithelial cells with electron microscopy. The islands contained no cells with myoepithelial characteristics. The findings show that there is no obvious participation of myoepithelial cells in the growth of the epi-myoepithelial islands.

The clinical picture of benign lympho-epithelial lesion

The histopathological diagnosis 'benign lympho-epithelial lesion' characterizes the major salivary gland disease in Sjögren's syndrome. It is not known if all cases with microscopically diagnosed benign lympho-epithelial lesion are variants of Sjögren's syndrome. The present clinical investigation showed that in 19 patients with the microscopical diagnosis of lympho-epithelial lesion, 84% fulfilled all criteria of Sjögren's syndrome. The rheumatoid factor and/or antinuclear factor was found in 84% and M-component was present in 16%. Sialography revealed sialectasis in all parotid glands. Salivary gland enlargement was found in 79%, and keratoconjunctivitis sicca in 89% of the patients. Systemic disease was found in 32%. The disease in the 2 patients with M-component took a malignant course, culminating in immunoblastic sarcoma and myelomatosis. The clinical diagnosis 'autoimmune sialadenitis' is proposed for the oral and salivary gland component is Sjögren's syndrome.

Experimental autoallergic sialadenitis in mice. Histopathological and ultrastructural studies

Experimental autoallergic sialadenitis was induced in SL/Ni mice by one or two injections of syngeneic submandibular gland homogenate emulsified with adjuvant. Light microscopically, there were marked lymphoid cell infiltration in the submandibular glands with high incidence and proliferation of duct epithelia. Furthermore complete alteration of whole glandular lobules in some cases was observed. Ultrastructurally, small and medium sized lymphocytes and plasma cells constituted a major portion of the infiltrating cells, and lymphocytes were frequently observed inside the basal lamina of ductal and acinar regions, especially observed in the small ductal region. In the aggregates of infiltrating cells, the cell remnants of salivary gland epithelia were scattered. Furthermore some of the epithelial cell remnants in aggregates of infiltrating cells could be recognized as epithelial masses which were composed of proliferated duct epithelial cells, though no typical structure of epimyoepithelial islands seen in Sjögren's syndrome was found. Antisalivary duct antibody was detected in only one case.

Immunoglobulin-containing plasma cells in chronic parotitis and malignant lymphomas of the parotid gland. Comparing immunocytochemical observations of frequency and localization

IgA-containing plasma cells in the periductal gland tissue are part of the special secretory immune system of the salivary glands. The reaction of Ig-containing plasma cells (localization, frequency, specific Ig-content) was analyzed by the indirect immunoperoxidase method in chronic recurrent parotitis (9 cases), chronic myoepithelial parotitis (benign lymphoepithelial lesion, Sjögren's syndrome; 8 cases), and malignant lymphoma associated with chronic myoepithelial parotitis (11 cases). The following results were obtained: 1. In chronic recurrent parotitis, parallel to the increase in IgA in the salivary secretion, a marked multiplication of IgA-containing plasma cells was found in the inflammatory infiltrate and the remaining non-inflamed periductal parenchyma of the parotid gland. In the marginal zone of inflammation, a slight increase of IgG-containing plasma cells was also observed. 2. In chronic myoepithelial parotitis, the total plasma cellular infiltration was slightly less distinct than in chronic recurrent parotitis. The most remarkable increase in Ig-containing plasma cells developed in the marginal zones--away from the myoepithelial cellular islands--as well as in the area of ductular proliferations, and was characterized by a strong increase of IgG-containing plasma cells. At the same time, a slight increase of IgM-containing plasma cells was observed. No plasma cells were found in the myoepithelial cellular islands. 3. In the malignant lymphomas associated with myoepithelial parotitis, which were mainly highly differentiated lymphomas (immunocytomas, centrocytic-centroblastic lymphomas) and rarely poorly differentiated immunoblastic lymphomas, there was a distinct decrease of IgG-containing plasma cells when compared with the numbers in this group without lymphoma. The differing degrees of prevalence and Ig-content of the plasma cells partly describe the change taking place in the local secretory immune system of the parotid gland. The possible relationships between chronic recurrent parotitis and auto-immune myoepithelial parotitis on one hand and the stages of transition (prelymphoma) to malignant lymphoma on the other, are discussed.

The autoimmune submandibular sialoadenitis of the NZB/NZW hybrid mice. A light and electron microscopical investigation

An electron microscopic study of the submandibular salivary gland lesion occurring in the NZB/NZW F1 hybrid mice was performed, and the findings were discussed and correlated to the autoimmune salivary gland disease observed in patients with Sjögren's syndrome. Within the submandibular salivary gland of this mouse strain focal infiltrates of mononuclear inflammatory cells were observed. Lymphoid cells were observed inside the basal lamina of acini and ducts, leading to destruction of these glandular units. The typical duct cell proliferation found in the autoimmune sialoadenitis of Sjögren's syndrome with the formation of the typical epimyoepithelial islands was not found in the submandibular glands of NZB/NZW mice.

Ultrastructural observations on the parotitis autoimmunica in the NZB/NZW hybrid mice

The lesions of the spontaneously occurring sialoadenitis in the parotid gland of New Zealand Black/New Zealand White (NZB/NZW) hybrid mice were studied with the light microscope and the electron microscope. The inflammatory mononuclear cell infiltrates of the glands observed adjacent to glandular vessels and ducts were found to consist of several different cell types. Lymphoid cells (large, medium sized and small lymphocytes) were the most common, but plasma cells, histiocytes and macrophages were also encountered. Furthermore lymphoid cells were frequently observed inside the basement membrane of acini as well as INTERcalated ducts. Evidence of cell damage of the epithelium invaded by lymphoid elements included loss of cytoplasmic density, vesiculation of the endoplasmic reticulum, the appearance of cytoplasmic vacuoles, and cellular lysis. All the animals studied displayed moderate to advanced glomerular, wire-loop lesions in the kidneys. The light and electron microscopic findings indicate that the parotitis in NZB/NZW mice is basically a vasculitis. Duct cell proliferation and epimyo-epithelial island formation, which are common features in Sjögren's syndrome, are totally lacking in the material studied.

A simple device measuring differences in level in the oesophagus

A device for measuring the difference in level between the pressure transducer and a point of measurment is described. It can be used in oesophageal manometry with waterfilled catheters to measure and compensate for superimposed hydrostatic pressure. The practical application of the method is illustrated.

[Carcinomas in papillary cystadenolymphomas of the parotid gland--definition and differential diagnosis (author's transl)]

Within a collective of 1431 salivavry gland tumors of the salivary gland register (1965--1976) an observation has been done, which has been classified as a "carcinoma in a papillary cystadenolymphoma". Corresponding to the "carcinoma in a pleomorphous adenoma" of the WHO-classification of salivary gland tumors the terminus "carcinoma in a cystadenolymphoma" is further defined. 6 additional cases from the literature are reviewed. The possible role of epithelial metaplasia and of a proceding radiation in the development of carcinomas in cystadenolymphomas are discussed. The following other tumors have to be differentiated from a carcinoma in a cystadenolymphoma: Metastases of other tumors beyond a cystadenolymphoma; malignant lymphoepithelial lesions (predominantly malignant lymphomas in a preexisting immune-sialadenitis of the myoepithelial sialadenitis type; rare carcinomas), and lymphoepitheliomas.

Classification of the pathohistology of diseases of the salivary glands - review of 2,600 cases in the Salivary Gland Register

Three major disease groups emerge from a classification of the pathohistology of 2,600 salivary gland preparations in the salivary gland register (from 1965 to 1974): salivary gland tumors (41%), salivary gland inflammations (26%), and sialadenosis (6%). Mucoceles (2%) and salivary gland cysts (1.5%) are seen less often. It is diagnostically important that lymph node changes in the area of the salivary glands (lymphadenitis, lymphomas, etc.) are worked up under suspicion of a primary salivary gland disease. Sialadenosis involves a primary, vegetative neuropathy, which is accompanied by enlargement of acinar cells. Under the heading of chronic sialdenitis, we fine 50% socalled Küttner tumors of the submandibular gland, 21% chronic relapsing parotitis, 14% chronic inflammations of the minor salivary glands and the sublingual gland, and 12% immune sialadenitis (myoepithelial sialadenitis in Sjögren's syndrome and epitheloid cell sialadenitis in Heerfordts syndrome). A more than average number of immune sialadenitis cases develop into malignant lymphomas (4 cases in the salivary gland register). The 1,067 tumor cases containing of 929 epithelial tumors (87%), 89 mesenchymal tumors (hemangiomas, lymphangiomas, lipomas, neurofibromas, sarcomas) and 49 metastases or periglandular tumors. Epithelial tumors were grouped on the basis of the World Health Organization (WHO) classification. Benign tumors (71.5%) consisted of pleomorphic adenomas (51.5%) and monomorphic adenomas (50%). After the pleomorphic adenomas, cystadenolymphomas (over 10%) represented the most frequent benign salivary gland tumor. On the basis of epithelial and stromal differentiation, pleomorphic adenomas were subdividied into four subtypes (stroma-rich and stroma-poor adenomas). The malignant tumors consisted of acinar cell tumors (2.5%), mucoepidermoid tumors (6%), and carcinomas at various levels of differentiation (adenoid-cystic carcinomas, 6.5%; adenocarcinomas, 2%; squamous cell carcinomas, 2%; carcinomas in pleomorphic adenomas, 4%; miscellaneous carcinomas - salivary duct carcinomas, clear-cell carcinomas, undifferentiated carcinomas, 5.5%). Differences in age and sex distribution, localization, malignity metastases, recidivism, et

[Morphology of salivary gland diseases]

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)