Epithelialmyoepithelial carcinoma expleomorphic adenoma of. Most common tumor of salivary glands three components, encapsulated, wellcircumscribed. The cases included 30 men and 21 women, ranging in. It is an interesting parallel that the myoepithelial cell with its hybrid epithelial and mesenchymal structural and functional phenotype has a dual role in such salivary gland tumors as pleomorphic adenoma. They also act as tumor suppressor and are considered very. Fnab specimens from salivary gland are difficult to diagnose for a number of reasons, including problems in sampling as well as difficulty in histological classification. Zarbo r j, prasad a r, regezi j a, gown a m, savera a t. Hypothyroidism was induced using propylthiouracil ptu for 4weeks. They envelop the glandular, acinar, and ductal elements of various organs, especially breast and salivary glands. Structure of salivary glands the working parts of the salivary glandular tissue figure 1. Neoplastically modified myoepithelial cells are also generally accepted to be a significant component of salivary gland tumors such as epithelial. The salivary glands arise as epithelial buds in the oral cavity between week 6 to 7 ga week 8 to 9 and extend into the underlying mesenchyme. Normal and neoplastic myoepithelial cells in salivary.
Pdf myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement. Myoepithelial cells reveal fibrils, and vesicular structures comparable to pinocytic or surface vesicles of smooth muscle cells. Pdf pathophysiology of myoepithelial cells in salivary glands. Myoepithelial cells are an important component of salivary gland tumors and are partly responsible for their diverse histology. Normal salivary glands and 55 salivary gland tumors were examined by immunostaining immunoperoxidase imp and immunofluorescence imf to identify myoepithelial cells mcs and speculate on their role in the histogenesis of the tumors.
Fortytwo albino wistar rats were divided into two main groups. Pleomorphic adenomas, salivary gland tumors, myoepithelial cells, s100 protein. Diagnostic dilemmas caused are due to inadequacy of characterizing the wide spectrum of morphologic and immunologic features which are different for both normal and neoplastic mecs. Primary clear cell tumors of the salivary glands include epithelial myoepithelial carcinoma, clear cell carcinoma, and clear cell myoepithelial carcinoma. They have been also noticed in mammary glands, lacrimal glands, prostate gland, and the.
Pdf cell proliferation in salivary gland adenocarcinomas. Fine needle aspiration cytology in diagnosis of salivary. Pdf clinical and pathological analysis of 10 cases of. Myoepithelial cells are the main component in pleomorphic. Neoplastic cells with myoepithelial differentiation are often present in both benign and malignant salivary glands neoplasms. Action of drugs on denervated myoepithelial cells of. We compared the immunoexpression of 5 myoepithelial cell mec markers asmoothmuscle actin, calponin, hcaldesmon, vimentin, and s100protein using 16 pleomorphic adenomas pa, 15 adenoid cystic carcinomas acc, and 3 epithelialmyoepithelial carcinomas emc of salivary glands.
Myoepithelial cell markers in salivary gland neoplasms cristiane. For example, adenoid cystic carcinomas often have translocations between. Epithelial myoepithelial carcinoma is a rare salivary gland tumor that most commonly arises in parotid gland. In addition, myoepithelial cells surround the end piece, their function being to assist in propelling the secretion into the ductal system. Get a printable copy pdf file of the complete article. Epithelial myoepithelial carcinoma of the parotid gland author.
These are contractile epithelial cells with smooth muscle like properties. An approach to the why is salivary gland pathology. Neoplastic cell features, as evaluated in haematoxylin and eosin stained histological sections and according to immunohistochemical characteristics, allow the identification of variable proportions of ductal and myoepithelial elements, together with a third cellular type, represented by basal cells, of uncommitted differentiation 35, 14. Ck 20 was by the extreme variability of morphological phenotype and negative. This cell is responsible for considerable proportions of the epithelial component of this tumor, including squamous metaplasia, and is also the agent principally involved in the synthesis, organization, and cytologic modifications of the chondromyxoid regions. Myoepithelial cells mecs are considered to be a key participant in most salivary gland diseases, particularly tumors. Epithelial myoepithelial carcinoma emca is a rare lowgrade salivary malignancy. Myoepithelial cells are cells usually found in glandular epithelium as a thin layer above the basement membrane but generally beneath the luminal cells. These tumors can occur at any age but are most common in young adults between the ages of 30 and 50, with the average of age in 36. Therefore, it is both important and interesting from the clinical aspect to determine whether or not proliferation and apoptosis of myoepithelial cells occur in. Myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary. The full expression of both morphogenesis and secretory cell differentiation in salivary glands is modulated. Diagnostic dilemmas caused are due to inadequacy of characterizing the wide spectrum of morphologic and immunol.
The total number of salivary gland tumors diagnosed in the institute from 1991 to 2005 was 1243, of which 51 were classified as myoepithelial carcinomas incidence, 4%. Sep 28, 2017 changes can cause salivary gland cells to become cancerous. Department of physiology, university of manitoba, winnipeg, canada. Although little is known about their biologic potential due to limited followup data, these tumors when in the lung clearly have the capacity to infiltrate and metastasize and therefore should be designated. Secretory cells of the salivary glands mucous triggered by. Myoepithelial cells are stellate or spindle shaped with 4 to 8 cytoplasmic processes. Salivary glands sg consist of three pairs of major sg, i. In mucous glands they tend to be arranged in a tubular configuration. Original article myoepithelial carcinoma of the salivary glands. It predominantly affects the oral cavity of adult females. Myoepithelial cell markers in salivary gland neoplasms. The nonneoplastic lesions involved only submandibular gland. Myoepithelial cells do not have a demonstrable secretory capability, but they can store glycogen in abundance. Cytochemical characterization of the myoepithelial cells in.
The initial diagnosis on cytological smears is difficult because of the overlapping morphological and cellular traits, so it is important to be aware of this entity during surgery, because local recurrences are common up to 41% in the absence of taking wide margins during excision. The benign salivary corpuscular bassinetmyoepithelioma. Salivary gland simple english wikipedia, the free encyclopedia. Apoptosis of myoepithelial cells in salivary glands was studied in atrophic rat parotid glands with tem by walker and gobe 1987, who failed to find apoptotic myoepithelial cells. Epithelial myoepithelial carcinoma of salivary glands. Conversely, sma was expressed in only 510% of the myoepithelial cells with moderate cytoplasm, and in 0% of the myoepithelial cells with naked nuclei fig.
Physiology, pathology and regeneration of salivary glands mdpi. Myoepithelioma or the myoepithelial adenoma is a benign myopeithelial neoplasm, composed of ectodermal contractile myoepithelial cells, which. Selective hypersensitivity to bradykinin in salivary glands with ligated ducts. Understanding the cellular and molecular control of salivary glands function is. Myoepithelioma is a rare benign tumor of salivary gland myoepithelial cells, most commonly as a spindle subtype. It is concluded that the myoepithelial cells of this gland normally receive motor impulses from both divisions of the autonomic nervous system, and that many, if not all, of the cells are innervated by both. Depending on the particular salivary gland, these acini are lined by variable combinations of mucous and serous epithelial cells surrounded by myoepithelial cells, located between the basal plasma membrane and the acinar basement membrane.
Secretory cells of the salivary glands mucous triggered by sympathetic stimuli e. Myoepithelial cells arise from the external epithelial layer and. They have been also noticed in mammary glands, lacrimal glands, prostate gland, and the sweat glands and have varied functions. Myoepithelial cell activation in the submaxillary salivary gland. Mucoepidermoid carcinoma hyalinizing clear cell carcinoma epithelial myoepithelial carcinoma acinic cell carcinoma the microscopic approach 1. Dec 12, 2011 myoepitheliomas are benign neoplasms of salivary glands derived from myoepithelial cells. Salivary gland neoplasms present with a diverse histological pattern which is mainly because of the presence of specialized myoepithelial cells mecs. Salivary glands tumors sgt are characterized ductal and myoepithelial cells were positive for ck14. Melanomas, lymphomas, and sarcomas are not included. The malignant counterpart is known as myoepithellial carcinoma or malignant myoepithelioma, which is quite. Does laser phototherapy influence the proliferation of. The behavior of salivary myoepithelial cells mec during chronic irradiation exposure is unknown. The patient was an 83yearold female, who suffered from swelling of the right parotid region.
This study aimed to investigate the response of mec to prolonged radiation exposure. These cells vary in their dominance and phenotypic expression. Myoepithelial cells sometimes referred to as myoepithelium are cells usually found in glandular epithelium as a thin layer above the basement membrane but generally beneath the luminal cells. Apoptosis and proliferation of myoepithelial cells in. Original article myoepithelial carcinoma of the salivary. Pdf evidence of a myoepithelial cell in tick salivary. These may be positive for alpha smooth muscle actin and can contract and expel the secretions of exocrine glands. Mar 20, 2020 background organ replacement regenerative therapy based on human adult stem cells may be effective for salivary gland hypofunction. Epithelial myoepithelial carcinoma emc is a rare neoplasm of the salivary glands. In mixed glands, the mucous acini are capped by a serous demilune. Moreover, devlin and sloan have shown that only the ductal cells and not in the neoplastic myoepithelial cells expressed the cartilagederived retinoic acidsensitive protein cdrap, a recently described immunomarker involved in the morphogenesis and the development of the salivary glands 49. Action of drugs on denervated myoepithelial cells of salivary glands.
Basic salivary gland pathology 1 basic salivary gland pathology jennifer l. In some salivary gland cancer cells, 2 chromosomes have swapped parts of their dna, which is called a translocation. Salivary gland myoepithelioma variants springerlink. This group of tumours is formed by cells that exhibit both epithelial and myoepithelial phenotypes and includes four entities. Pdf myoepithelial cellrich pleormorphic adenoma of. Pdf myoepithelial cells mecs are considered to be a key participant in most salivary gland diseases, particularly tumors. A salivary gland can consist of a varied mixture of these types of end pieces. Myoepithelial cells in salivary gland tumorsrevisited. Myoepithelial cells mec of the salivary glands in health and. The aim was to evaluate the expression of smooth muscle actin sma, calponin, caldesmon, cd10, cd29, s100 protein, glial fibrillary acidic protein gfap and p63 in myoepithelial cells during salivary gland.
The aim of this study was to evaluate the influence of laser phototherapy on myoepithelial cells of salivary glands of hypothyroid rats. Myoepithelial carcinoma arising in pleomorphic adenoma of. There are three main types of cells in the major salivary glands. A major roadblock in the histologic classification of salivary gland neoplasms is that the majority of them arise from the same cell lines epithelial and myoepithelial. We compared the immunoexpression of 5 myoepithelial cell mec markers asmoothmuscle actin, calponin, hcaldesmon, vimentin, and s100protein using. End pieces may contain mucous cells, serous cells or a mixture of both. Clear cell myoepithelial carcinoma of salivary glands showing ewsr1 rearrangement. The glands are inside a capsule, of connective tissue. Generation of functional salivary gland tissue from human. They are found in the sweat glands, mammary glands, lacrimal glands, and salivary glands. The three paired groups of salivary glands are named by their anatomical location.
Stroma stroma eosinophilic hyaline material myoepithelial cells intraluminal material ductal cells stromal mucin common. Patients with carcinomas of the salivary glands protocol applies to all invasive carcinomas of the parotid, submandibular, and sublingual glands. Mecs structurally resemble both epithelial cells and smooth muscles. Wehavefoundonly onecase fromthe united kingdomdescribed 419 as epithelial myoepithelial carcinoma,12 although the parotid clear cell adenoma reported by corridan in 1956 was almost certainlyanother. Myoepithelial cells mecs are one of the nonsecretory components of salivary gland acini. According to dardick and his collaboratories, the histogenetic model of these tumors is based on the myoepithelial cell capacity from the proliferating units of ductallike type or solidinsular. Achtstatter t, moll r, anderson a, kuhn c, pilz s, schwechheimer k, franke ww 1986 expression of glial filament protein gfp in nerve sheaths and nonneural cells reexamined using monoclonal antibodies, with special emphasis on the coexpression of gfp and cytokeratins in epithelial cells of human salivary gland and pleomorphic adenoma. Ultrastructural mapping of salivary gland innervation in. However, the generated tissues are immature because the signaling factors that induce the differentiation of human salivary gland stem cells into salivary glands are unknown. Apoptosis of myoepithelial cells in salivary glands was studied in atrophic rat pa.
Hyalinizing clear cell carcinoma is a lowgrade neoplasm of the minor salivary gland composed exclusively of epithelial cells a nd not myoepithelial cells. Most of them behave in a benign fashion and are designated as myoepithelioma. Pathophysiology of myoepithelial cells in salivary glands. Major salivary glands college of american pathologists. Myoepithelial cells are smooth muscle like cells having epithelial origin. Myoepithelial cells contractile cells occur between secretory cells and basal lamina stellate around serous acini longitudinal. Pdf the ultrastructural aspects of neoplastic myoepithelial. Tumors constituted predominantly of myoepithelial cells are designated as myoepitheliomas.
The ambiguous salivary myoepithelial cells the journal of. Histopathologically, the carcinomas are characterized by a dual cell population of epithelial ductal cells and myoepithelial cells. Abstract it is an interesting parallel that the myoepithelial cell with its hybrid epithelial and mesenchymal structural and functional phenotype has a dual role in. Based on the final histologic diagnosis, eight cases 10% were nonneoplastic and the rest were neoplasms. The clinical features of the 51 cases of myoepithelialcarcinomasaresummarizedin table 1 andtable 2. Myoepithelial cells in these cases constitute the basal cell layer of an epithelium that harbors the epithelial progenitor. They play vital role during expulsion of saliva and regulates the electrolytic exchange. Sonkhya and shubha gupta, journalcase reports in otolaryngology.
Epithelialmyoepithelial carcinoma of the lung wikipedia. Myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement membrane. These cells present some architectural characteristics of sm cells caveolae, microfilaments, and dense bodies and display contractile properties that allow ejection of fluids including sweat and milk. Most myoepitheliomas affect the parotid gland and minor salivary glands of the palate 2, 7. Myoepithelial cell activation in the submaxillary salivary. Myoepithelial carcinoma, also know as malignant myoepithelioma, is rare in the salivary gland, and its cytologic features have rarely been reported. Differential diagnosis between oral metastasis of renal cell. The presence of a myoepithelial cell in the gland of an arthropod is unusual. Four cases of myoepithelial carcinoma with cytology were retrieved from the archives of the pathology departments of two academic institutes. Therole playedbythe myoepithelial cell in salivation hasengagedthe interest of many investigators, since krause described basket cells surrounding the acini in the cat parotid gland krause, 1865. Minor salivary gland carcinomas are detailed in upper aerodigestive tract sitespecific protocols.
The classic c mcs of normal salivary glands stained by imp. Cytochemical characterization of the myoepithelial cells. Lanthanumimpregnated preparations of the gland reveal that many of these vesiclelike structures are, in fact, invaginations of the plasma membrane and are continuous with the extracellular space. In salivary glands, the myoepithelial cells that surround the intercalated ducts are spindled in contrast to the large stellate ones that envelop the acini. Discussion p63 is expressed in basalstem cells of strati. It is microscopically characterized by hyaliniz ing stroma. It is rare for emca to occur as the carcinomatous component of carcinoma expleomorphic adenoma pa. Plasmacytoid myoepithelioma of minor salivary glands.
Diagnostic dilemmas caused are due to inadequacy of characterizing the wide spectrum of morphologic and immunologic features which are different for both. We examined one additional case of emca expa, immunohistochemically and genetically. If have symmetric enlargement of salivary glands with. Epithelialmyoepithelial carcinoma of salivary glands. In some tumors of the salivary glands, myoepithelial cells do not participate in histogenesis. Hyalinizing clear cell carcinoma of minor salivary gland. Pdf clear cell myoepithelial carcinoma of salivary. They are specialized cells capable of contraction aiding in the expulsion of saliva. Myoepithelial cell an overview sciencedirect topics. Myoepithelial cells are believed to be of ectodermal origin.
Introductioninformation on the proliferation characteristics of normal and neoplastic human salivary gland tissues is scarce, especially in salivary gland carcinomas that express dual differentiation 3,5,14,16,19,20,22. They are present in salivary glands, mammary gland, sweat gland and lacrimal gland. Tumors that consist exclusively of myoepithelial cells are. These tumors arise from portions of the salivary duct system in which myoepithelial cells are not normally found. Epithelialmyoepithelial carcinoma of the parotid gland.
Myoepithelial cells in salivary gland tumorsrevisited dardick. Myoepithelial cellrich pleormorphic adenoma of minor. The focal resemblance to other salivary gland type tumors may cause diagnostic difficulties, particularly in small endobronchial biopsies. Mecs have a contractile function that, perhaps as in the salivary and mammary glands, helps expel the secreted fluid fig.
Pathophysiology of myoepithelial cells in salivary glands shah aa. Apoptosis and proliferation of myoepithelial cells. Methods isolated human submandibular gland stemprogenitor cells hsmgepispcs were. Cell proliferation in salivary gland adenocarcinomas with myoepithelial participation. Clear cell salivary gland tumors although clear cell salivary gland tumors, which constitute less than 1% of all primary salivary gland tumors 20, are often malignant in nature, they include two types of benign lesions. Bottomup assembly of salivary gland microtissues for. Diagnostic dilemmas caused are due to inadequacy of characterizing. Ck14 is a marker of multipotent stem cells that give rise to various salivary gland components e. Pdf pathophysiology of myoepithelial cells in salivary. Secretions from the epithelial cells are contained in apical granules.
Myoepithelial cells mcs are modified epithelial cells found in sweat, mammary, salivary, lacrimal, and tracheobronchial glands. Epithelial myoepithelial carcinoma comprises intercalated ductlike structures with an inner component of epithelial cells, surrounded by an outer component of clear myoepithelial cells. These changes often activate genes that affect cell growth. Salivary gland neoplasms composed exclusively or predominantly of myoepithelial cells are relatively uncommon and constitute. Salivary gland basal cell and canalicular adenomas. Detection of myoepithelial differentiation both in aspiration cytology and histologic examination can also help diagnosing a tumor as of salivary gland type 12. In three cases, the specimens were obtained by fine needle aspiration biopsy fna. Solid nonmyxoid, myxoid pleomorphic adenomalike, reticular canalicularlike or mixed patterns of myoepithelial cells with no ductal differentiation. Myoepithelial cells are important components of salivary gland structure, aiding the expulsion of saliva from acinar lobules. Situated between the acinar epithelium and the basement membrane, human salivary gland myoepithelial cells hsmecs are characterized by their dual epithelial and smooth muscleassociated expression profile.
Cytology of myoepithelial carcinoma of the salivary gland. Myoepithelioma of the salivary gland was formally categorized as a salivary neoplasm in 1991 2,3. Salivary gland tumors university of california, davis. In salivary glands of other arthropods, fluid is moved to the outside either by pressure of the hemolymph on the elastic duct system or by extrinsic muscles associated with a reservoir such as in the cockroach. This unique proteome comprises smooth muscle cytoskeletal elements and contractile machinery.
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