Dec 01, 1987 myoepithelial cells bordered acini, intercalated ducts, and occasionally striated ducts of the major salivary glands. Some illustrations are courtesy of mcgrawhill chapter 17 lecture. Generation of functional salivary gland tissue from human. Cytology of myoepithelial carcinoma of the salivary gland. A salivary gland can consist of a varied mixture of these types of end pieces. The minor salivary glands are not surrounded by a capsule but are embedded within the connective tissue. In salivary glands and other exocrine organs, there are starfishshaped cells that lie between the basal lamina and the acinar and ductal cells. Myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement membrane. Molecular profiling of clear cell myoepithelial carcinoma. Skalova a, weinreb i, hyrcza m, simpson rh, laco j, agaimy a, vazmitel m, majewska h, vanecek t, talarcik p, manajlovic s, losito sn, steiner p, klimkova a, michal m am j. Myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary glands. Sialadenitis can be further classed as acute or chronic. The pharmacology of salivary myoepithelial cells in dogs. Myoepithelial cells mecs are one of the nonsecretory components of salivary gland acini.
These changes often activate genes that affect cell growth. Pdf malignant myoepithelioma of the salivary glands. Action of drugs on denervated myoepithelial cells of salivary. Secretions from the epithelial cells are contained in apical granules. These are contractile epithelial cells with smooth muscle like properties. 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. More specifically, branching of lacrimal and salivary glands is. Normal and neoplastic myoepithelial cells in salivary glands.
Myoepithelial carcinoma of salivary glands is an underrecognized and challenging entity with a broad morphologic spectrum, including an ewsr1rearranged clear cell variant. These markers, together with smooth muscle actin may be useful tools for identifying myoepithelial cells. 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. Mucoepidermoid carcinoma hyalinizing clear cell carcinoma epithelial myoepithelial carcinoma acinic cell carcinoma the microscopic approach 1. Clear cell myoepithelial carcinoma of salivary glands showing ewsr1 rearrangement. Recently novel markers of myoepithelium have been studied, such as calponin calp, caldesmon cald, and smooth muscle myosin heavy chain. Normal and neoplastic myoepithelial cells in salivary. Diagnostic dilemmas caused are due to inadequacy of characterizing.
Salivary glands tumors sgt are characterized ductal and myoepithelial cells were positive for ck14. Diagnostic dilemmas caused are due to inadequacy of characterizing the wide spectrum of morphologic and immunologic features which are different for both. Tumors that consist exclusively of myoepithelial cells are. They have been also noticed in mammary glands, lacrimal glands, prostate gland, and the. Myoepithelial sialadenitis mesa is the reactive salivary gland lymphoid infiltrate that occurs in patients with sjogrens syndrome. Epithelial myoepithelial carcinomas comprise approximately 1 % of all salivary gland neoplasms.
In addition, myoepithelial cells surround the end piece, their function being to assist in propelling the secretion into the ductal system. In the case of submandibular gland, in man there is increase in secretion but the amount is small and the secretion is thick and viscous due to high mucin content. Sep 28, 2017 changes can cause salivary gland cells to become cancerous. Cell signaling regulation in salivary gland development. In mixed glands, the mucous acini are capped by a serous demilune. They are specialized cells capable of contraction aiding in the expulsion of saliva. In salivary glands, the myoepithelial cells that surround the intercalated ducts are spindled in contrast to the large stellate ones that envelop the acini. They are surrounded by contractile myoepithelial cells usually with only a flat nucleus seen. 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. An approach to the why is salivary gland pathology. Ck 19 was positive in luminal ductal cells, but negative in acinar, basal ductal and myoepithelial cells. Get a printable copy pdf file of the complete article. Myoepithelial cells have contractile properties and exhibit a dual epithelial and smooth muscle phenotype. They play vital role during expulsion of saliva and regulates the electrolytic exchange.
Selective hypersensitivity to bradykinin in salivary glands with ligated ducts. Sialadenitis sialoadenitis is inflammation of salivary glands, usually the major ones, the most common being the parotid gland, followed by submandibular and sublingual glands. Salivary secretion in human beings digestive system. Myoepithelial cells are believed to be of ectodermal origin. Salivary gland individual secretory acini are drained by intercalated ducts and join striated ducts striated ducts drain into a series of interlobular ducts serous and mucous acini. Apoptosis and proliferation of myoepithelial cells in. The protein p63 was present in all stages of salivary gland morphogenesis from initial bud to terminal bud stage.
Myoepithelial differentiation markers in salivary gland. Myoepithelial cell activation in the submaxillary salivary gland. 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. Pathophysiology of myoepithelial cells in salivary glands.
There are three main types of cells in the major salivary glands. The salivary duct system is entirely epithelial in origin. Myoepithelial cells are flat, stellate cells present in exocrine tissues including the salivary glands. Salivary glands tumors sgt are characterized ductal and myoepithelial cells were. They are preponderantly tumors of the parotid glands with a relatively low mortality but a. Currently, however, it is accepted that myoepitheliomas and pleomorphic adenomas represent. The structure and function of myoepithelial cells in salivary glands. Although they are an important element in many salivary gland tumors, 1 pure myoepitheliomas are rare, accounting for salivary gland tumors. Vimentin was demonstrated in stromal fibroblasts and endothelial cells of the vasculature. Action of drugs on denervated myoepithelial cells of. Neoplastically modified myoepithelial cells are also generally accepted to be a significant component of salivary gland tumors such as epithelial. They are preponderantly tumors of the parotid glands with a relatively low mortality but a decided locoregional aggressiveness.
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 cells are important components of salivary gland structure, aiding the expulsion of saliva from acinar lobules. They envelop the glandular, acinar, and ductal elements of various organs, especially breast and salivary glands. Proteins gfap, cd10 and caldesmon were not observed in myoepithelial cells of salivary glands. These results are consistent with those of previous ultrastructural and immunohistochemical studies for contractile proteins.
Pdf myoepithelials are found in sweat glands, mammary glands, lacrimal glands, and salivary glands. Clear cell myoepithelial carcinoma arising from the hard. Salivary gland tumors university of california, davis. Salivary gland simple english wikipedia, the free encyclopedia. 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.
Myoepithelial cells mcs are modified epithelial cells found in sweat, mammary, salivary, lacrimal, and tracheobronchial glands. Salivary gland malignant myoepithelioma nagao 1998. They also act as tumor suppressor and are considered very. Epithelialmyoepithelial carcinoma of salivary glands john. Clear cell myoepithelial carcinoma is a rare variant with an aggressive behavior. Striated ducts with simple columnar epithelium gather secretions from. Although it is well established that mucosaassociated lymphoid tissue malttype lymphomas may develop from mesa, the issue of whether monoclonal b cell populations in early mesaassociated lesions represent malt lymphomas or more benign types of expansions. The major include the paired bilateral parotid, submandibular and sublingual glands. Cytochemical characterization of the myoepithelial cells in. Pdf clear cell myoepithelial carcinoma of salivary. Myoepithelial cell an overview sciencedirect topics. While myoepithelial cells have been studied extensively in mammary and lacrimal gland tissues, less is known of the function of myoepithelial cells derived from human salivary glands. Mecs structurally resemble both epithelial cells and smooth muscles. End pieces may contain mucous cells, serous cells or a mixture of both.
Myoepithelial cells in salivary gland tumorsrevisited. 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. The presence of betareceptors in the submaxillary gland of the dog. 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. Pathophysiology of myoepithelial cells in salivary glands ncbi nih. Epithelialmyoepithelial carcinoma of salivary glands.
In rat salivary glands alkaline phosphatase and adenosine triphosphatase are readily localized in the myoepithelial cells and nad diaphorase and malic. Also, the accessory digestive organs contribute antibodies and antibacterialviral growth substances. Myoepithelial cells are smooth muscle like cells having epithelial origin. Epithelialmyoepithelial carcinoma of the parotid gland. Myoepithelial cells are the main component in pleomorphic. Pdf pathophysiology of myoepithelial cells in salivary glands. Myoepithelial cells reveal fibrils, and vesicular structures comparable to pinocytic or surface vesicles of smooth muscle cells. Small cell oat cell carcinoma of minor salivary gland origin. Myoepithelial cells mecs are considered to be a key participant in most salivary gland diseases, particularly tumors. Collina g, gale n, visona a, betts cm, cenacchi v, eusebi v. Myoepithelial cells mec of the salivary glands in health.
Myoepithelial cell markers in salivary gland neoplasms. The full expression of both morphogenesis and secretory cell differentiation in salivary glands is modulated. In some salivary gland cancer cells, 2 chromosomes have swapped parts of their dna, which is called a translocation. Differential diagnosis between oral metastasis of renal. Primary clear cell tumors of the salivary glands include epithelial myoepithelial carcinoma, clear cell carcinoma, and clear cell myoepithelial carcinoma. They are interposed between the secretory cells and the basal lamina. Myoepithelioma is a benign tumor composed of cells with myoepithelial differentiation lacking the typical chondromyxoid matrix found in pa. Myoepithelioma is a rare tumor of myoepithelial cells that was recognized as a distinct entity by the world health organization in 1991. For example, adenoid cystic carcinomas often have translocations between. 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. Myoepithelial cells are present in organs other than the breast e. The glands are inside a capsule, of connective tissue.
Acini myoepithelial cells vs serous demilunes crescent of giannuzzi myoepithelial cells are flattened with flattened nuclei serous demilunes. Myoepithelial cells in salivary gland tumorsrevisited dardick. Here, we describe a case of clear cell myoepithelial carcinoma arising from the hard palate in an elderly male who underwent resection of the tumor and postop radiation. This cell is responsible for considerable proportions of the epithelial component of this tumor, including squamous metaplasia, and is also the agent principally. Lg epithelium is composed of ductal, acinar, and myoepithelial cells mecs. Bottomup assembly of salivary gland microtissues for. Pdf myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement. The myoepithelial cells are indeed a fascinating type of cell, in that they appear to belong to two widely divergent types of tissues, namely the epithelium and the mesenchyma. If have symmetric enlargement of salivary glands with. Understanding the cellular and molecular control of salivary glands function is. Pleomorphic adenomas, salivary gland tumors, myoepithelial cells. Epithelial myoepithelial carcinoma of salivary gland with metastasis to lung. The present immunohistochemical study showed that normal myoepithelial cells in major and minor salivary glands contain actin and myosin, which are major constituents of myofilaments. Myoepithelial carcinoma is an uncommon tumor of the salivary glands, most commonly the parotid gland.
Stroma stroma eosinophilic hyaline material myoepithelial cells intraluminal material ductal cells stromal mucin common. Physiology, pathology and regeneration of salivary glands mdpi. Epithelial myoepithelial carcinoma of the parotid gland author. Two specific markers for myoepithelial cells in the normal salivary gland, musclespecific actin and cytokeratin 14, were both variably, independently. Dedifferentiated acinic cell carcinoma of the parotid. All the mme developed from a benign preexistent tumor. Update on selected salivary gland neoplasms archives of. The myoepithelial tumors were composed of epithelioid, plasmacytoid, spindle, or clear cell types, and they showed a solid or a myxoid pattern of growth. Defining the morphology of adult human salivary glands.
Sympathetic stimulation causes contraction of myoepithelial cells. Basic salivary gland pathology 1 basic salivary gland pathology jennifer l. Ck 20 was by the extreme variability of morphological phenotype and negative. Myoepithelial cells arise from the external epithelial layer and. Myoepithelial carcinoma is generally aggressive with largely unknown genetic features. It should not be confused with sialadenosis sialosis which is a noninflammatory enlargement of the major salivary glands. Cd29, s100 and calponin were detected increasingly as salivary gland structure matured and in fully developed salivary gland. The identification and the role of the myoepithelial cell in salivary gland. Pdf myoepithelial cells mecs are considered to be a key participant in most salivary gland diseases, particularly tumors. Epithelial myoepithelial carcinoma comprises intercalated ductlike structures with an inner component of epithelial cells, surrounded by an outer component of clear myoepithelial cells. This unique proteome comprises smooth muscle cytoskeletal elements and contractile machinery. Neoplastic cells with myoepithelial differentiation are often present in both benign and malignant salivary glands neoplasms. Ck14 is a marker of multipotent stem cells that give rise to various salivary gland components e.
These may be positive for alpha smooth muscle actin and can contract and expel the secretions of exocrine glands. Action of drugs on denervated myoepithelial cells of salivary glands. The evolving definition of salivary gland stem cells npj. Pdf clear cell myoepithelial carcinoma of salivary glands. 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. Methods isolated human submandibular gland stemprogenitor cells hsmgepispcs were. Diagnostic dilemmas caused are due to inadequacy of characterizing the wide spectrum of morphologic and immunol. Normal anatomy salivary glands have a glandular structure with tubules, secretory acini and myoepithelial cells to produce and secrete saliva.
Salivary glands sublingual glands have mainly mucous acini. In the clear cell dominant type, 9095% of the myoepithelial cells with clear cytoplasm, and 8590% of the naked cells showed p63positive expression, whereas 5565% of the myoepi. Pdf pathophysiology of myoepithelial cells in salivary. Submandibular glands have a mixture of mucous and serous acini. Intercalated ducts small diameter lined by small cuboidal cells nucleus located in the center welldeveloped rer, golgi apparatus, occasionally secretory granules, few microvilli myoepithelial cells are also present intercalated ducts are prominent in salivary glands having a watery secretion parotid. 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. Salivary gland tumors frequently present myoepithelial cell differentiation that is not always easily identified on routinely stained sections. Myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement. They are present in salivary glands, mammary gland, sweat gland and lacrimal gland. Immunohistochemically they are found to contain keratin intermediate filaments 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. Myoepithelial cells are stellate or spindle shaped with 4 to 8 cytoplasmic processes. The ambiguous salivary myoepithelial cells the journal of. Myoepithelial cell activation in the submaxillary salivary. Salivary glands and pancreas secretes digestive juices and liver secretes bile salivary glands lubricates liver stores nutrients and cleans the blood. Salivary secretion is brought about by reflex action. Role of liver, gall bladder, salivary glands, and pancreas. The nuclei of the myoepithelial cells were often larger than those of the ductal cells. Myoepithelioma of salivary gland pdf download 16tijh. Pdf actin versus vimentin in myoepithelial cells of. In addition, myoepithelial cells surround the end piece, their function being to assist in propelling the secretion into. Mar 20, 2020 background organ replacement regenerative therapy based on human adult stem cells may be effective for salivary gland hypofunction. Clear cell carcinoma consists exclusively of luminal. In a qualitative analysis of salivary glands, myoepithelial cells were identified around mucous and.
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