Myoepithelial carcinoma is a rare malignant cancerous tumor that usually occurs in the salivary glands in the mouth, but can also occur in skin and soft tissues. Immunofluorescence analysis of k5 and k14 expression revealed robust expression of these keratins in msgc grown as both monolayers and 3dspheroids fig 2a. Contractile epithelial cells resembling smooth muscle cells that are present in glands, notably the mammary gland, and aid in secretion explanation of myoepithelial myoepithelial article about myoepithelial by the free dictionary. Myoepithelial cells mec of the salivary glands in health. Salivary gland cancer treatment options include surgery with or without postoperative radiation therapy, radiation therapy, and chemotherapy. They most commonly affect the major and minor salivary glands with the parotid gland being the most common, approximately 40%. In adult salivary glands, k5 expression is restricted to intercalated and basal excretory ducts and myoepithelial cells. Parotid, submandibular, and sublingual glands are the major salivary glands. In the case of wound healing, myoepithelial cells reactively proliferate. These cells structurally resemble epithelial cells and smooth muscles and, thus, are referred to as myoepithelial cells mecs. Epithelialmyoepithelial carcinoma of parotid gland a. Around ducts they are fusiform in shape and surround the periphery of ducts in a way analogous to barrel hoops. Fine needle aspiration biopsy of salivary gland lesions 2.
In other taxa such as insects, salivary glands are often used to produce biologically important proteins such as silk or glues. Myoepithelial cell markers in salivary gland neoplasms cristiane. Myoepithelial article about myoepithelial by the free. Salivary gland myoepithelial carcinoma mc or malignant myoepithelioma is a rare entity. It is assumed that they take part in the expulsion of the saliva, and possibly they support the structures against a distension during secretion. Myoepithelial cells are contractile cells with respect to intercalated and secretory endpieces. Pdf myoepithelial cells mecs are considered to be a key participant in most. Myoepithelioma is usually a benign tumor arising from neoplastic myoepithelial or basket cells which are found between the basement membrane and the. Myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement membrane. Epithelialmyoepithelial carcinoma of the parotid gland.
In view of the pivotal role played by these myoepithelial cells in various salivary gland neoplasms, their identification and detection is an important link in the study of salivary gland tumors. Histological examination of the second recurrence showed a malignant spindle cell. The myoepithelial cells were located at the base of the acinar cells as well as intercalated and striated ducts, and were stellate in shape. Myoepithelial cells are found in exocrine glands, including highly developed glands, such as the breast, where they form a major population surrounding glandular acini and ducts, and squeeze secretions from the glandular lumina. Pdf epithelialmyoepithelial carcinoma of the parotid gland. Review and updates of immunohistochemistry in selected salivary gland and head and neck tumors shaobo zhu, md. Jan 29, 20 myoepithelial cells in health where it is found. Only 1% of all salivary gland neoplasms are myoepitheliomas. Myoepithelial cells in these cases constitute the basal cell layer of an epithelium that harbors the epithelial progenitor. In salivary glands and other exocrine glands, there are starshaped cells lying between the basal lamina and the acinar and ductal cells. Myoepithelial cell an overview sciencedirect topics. Immunohistochemistry is a useful tool for diagnosing salivary gland and head and neck tumors. Mecs play an important role in supporting the morphogenesis, differentiation and polarization of salivary acini. Epithelial myoepithelial carcinoma emc is a rare biphasic tumor of the salivary glands typically.
Myoepithelial cells do not have a demonstrable secretory capability, but they can store glycogen in abundance. Primary clear cell tumors of the salivary glands include epithelial myoepithelial carcinoma, clear cell carcinoma, and clear cell myoepithelial carcinoma. Intraosseus salivary gland tumor with prominent cytoplasm clearing include epithelialmyoepithelial carcinoma myoepithelial cell are immunoreactive for s100 protein, vimentin. The acini cells are surrounded by contractile cells called as myoepithelial cells basket cells, which are responsible for the flow of secretions of saliva by contraction of the cell. Myoepithelial cell article about myoepithelial cell by.
Epithelialmyoepithelial carcinoma of salivary gland. Latin myoepitheliocytus myoepithelium usually found in the glandular epithelium above basement membrane and beneath luminal cellsfound in the sweat glands, mammary glands, lacrimal glands, and salivary glands 5. Basic salivary gland pathology 1 basic salivary gland pathology jennifer l. These cells vary in their dominance and phenotypic expression.
They envelop the glandular, acinar, and ductal elements of various organs, especially breast and salivary glands. Myoepitheliomas mostly occur in salivary glands, as well as in breast, skin, and lung. Mc usually presents as a slowgrowing painless mass arising in the parotid gland, but may involve other salivary glands. Pdf pathophysiology of myoepithelial cells in salivary glands. Rangoonwala college of dental sciences and research centre, azam campus, pune, maharashtra, india. Characterization of the myoepithelial cells in the major. Myoepithelial cells are ectodermally derived contractile cells that act as smooth muscle cells. Salivary glands have proven to be very useful to students of genetics due to the occurrence of polytene chromosomes that are common in the salivary gland cells of many diptera. Myoepithelial definition of myoepithelial by medical. Get detailed information about the treatment for newly diagnosed and recurrent salivary gland cancer in this summary for clinicians. We immunohistochemically investigated the distribution of cells expressing podoplanin in mouse major salivary glands by laserscanning microscopy. The histopathology shows several architectural patterns such as trabecular, glandular, partly cystic, and solid.
Tani, lambert skoog, in comprehensive cytopathology third edition, 2008. Myoepithelial tumors of the salivary gland including myoepitheliomas benign and. The secretory end pieces and intercalated ducts are associated with stellate shaped contractile cells called the myoepithelial cells. Epithelial myoepithelial carcinoma comprises intercalated ductlike structures with an inner component of epithelial cells, surrounded by an outer component of clear myoepithelial cells. Pdf download for myoepithelial cell markers in salivary gland neoplasms.
Myoepithelial cell markers in salivary gland neoplasms. Subtyping salivary gland neoplasm of uncertain malignant. Neoplastic cells with myoepithelial differentiation are often present in both benign and malignant salivary glands neoplasms. Myoepithelial cell definition of myoepithelial cell by. Clear cell myoepithelial carcinoma of salivary glands. Approximately 66% of these tumors occur in a part of the salivary gland, known as the parotid gland.
Abstract salivary glands are essential organs that produce and secrete. Microscopic examination shows that myoepithelial cells are thin and spindleshaped and situated between the basement membrane and epithelial cells. The initial tumour was a pleomorphic adenoma with epithelial and myoepithelial elements. In some tumors of the salivary glands, myoepithelial cells do not participate in histogenesis. In the terminal portion of the salivary glands, myoepithelial cells. Mecs structurally resemble both epithelial cells and smooth muscles. The cells are called myo epithelial due to the fact that. Sep 10, 2018 epithelial myoepithelial carcinoma emc of salivary gland is a malignant epithelial tumor, composed of two distinct cell types, affecting either the major or minor salivary glands.
The clinical features of the 51 cases of myoepithelial carcinomas are summarized in table 1 and table 2. Myoepithelial cells in salivary gland tumorsrevisited. Dec 01, 2018 myoepithelial carcinoma of salivary gland is a malignant epithelial tumor, composed almost only of myoepithelial cell type, affecting either the major or minor salivary glands. Expression of podoplanin in the mouse salivary glands. Epithelial myoepithelial carcinoma is a relatively uncommon malignant neoplasm. Collina g, gale n, visona a, betts cm, cenacchi v, eusebi v. The expression of endothelial cell marker pecam1 was tested to discriminate lymphatic endothelium from salivary gland cells, and myoepithelial cells were identified by an antibody for pcadherin. The cell types encountered were epithelioid, stellate, plasmacytoid, spindle, clear. In salivary glands and other exocrine glands, there are starshaped cells lying. Myoepithelial cells are believed to be of ectodermal origin.
A variety of diseases, such as cancer, autoimmune diseases, infections and physical traumas, can alter the functionality of these glands, greatly impacting the quality of life of patients. In mixed glands, the mucous acini are capped by a serous demilune. Proliferative activity of myoepithelial cells in irradiated. Neoplastic myoepithelial cells in both benign and malignant tumors can take several forms, including epithelioid, spindle, plasmacytoid, and clear, and this variability largely accounts for difficulties in histopathological diagnosis. Pulmonary epithelial myoepithelial carcinoma pemc is a rare subset of salivary gland type tumors of the lung. Salivary gland myoepithelial carcinoma springerlink. A myoepithelial carcinoma, a rare malignant salivary gland neoplasm, arose in a pleomorphic adenoma of the parotid gland. Formerly considered a variant of pleomorphic adenoma. We compared the immunoexpression of 5 myoepithelial cell mec markers. Sympathetic stimulation caused no pressure rise when a single stimulus was given but only when repetitive stimulation was used at a frequency approaching that required for secretion. Myoepithelial carcinoma malignant myoepithelioma of the. Immunocytochemistry of myoepithelial cells in the salivary glands. Epithelialmyoepithelial carcinoma of salivary glands john.
Myoepithelial cells are cells usually found in glandular epithelium as a thin layer above the basement membrane but generally beneath the luminal cells. Pdf myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial. Myoepithelial cells mecs, which support and facilitate the expulsion of saliva from the secretory portions of salivary glands, are very important for their function. Primary myoepithelial carcinoma of palate world journal of. The distribution of these myoepithelial cells varies considerably between types of glands and even during the course of glandular development. They are found in the sweat glands, mammary glands, lacrimal glands, and salivary glands. Proliferative activity of myoepithelial cells in normal salivary glands. Cells physiology, pathology and regeneration of salivary glands. The inner cells were epithelial and the outer cells myoepithelial, the latter usually. Myoepithelial cells surround the acini but have also been found around intercalary and striated ducts. These tumors arise from portions of the salivary duct system in which myoepithelial cells are not normally found. Neural control of salivary myoepithelial cells emmelin. Keratin 5 k5 and k14 are epithelial cell markers that are typically expressed in both the basal cells of the ducts and the myoepithelial cells of the adult salivary gland 2426. Using the kaplanmeier survival curve, we found the mean diseasefree survival time to be 31.
Histopathologically, the carcinomas are characterized by a dual cell population of epithelial ductal cells and myoepithelial cells. Around acini, myoepithelial cells have a stellate, multiprocessed morphology in three dimensions and form a contractile meshwork, which encloses secretory units of glands. We explore histopathologic, histochemical, electron microscopic and immunohistochemical aspects and discuss histologic grading, histogenesis, animal models, and genetic events. Myoepithelial cells are stellate or spindle shaped with 4 to 8 cytoplasmic processes.
Myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement. They play vital role during expulsion of saliva and regulates the electrolytic exchange. Four cases of epithelial myoepithelial carcinoma of the salivary glands arose as painless masses in patients over 60 years old, three in the parotid and one in the submandibular gland. Salivary gland cytopathology acgme competency checklist. Myoepithelial cells mec of the salivary glands in health and. Epithelialmyoepithelial carcinoma of salivary glands. The histology of the tumor shows a biphasic pattern with clear myoepithelial cells encasing ducts with an epithelial lining.
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 definition of myoepithelial by the free. The minor salivary glands are labial and buccal gland, glossopalatine gland, and palatine and lingual glands. The physiological role of these cells in salivary glands is remarkably little known. Myoepithelial cells in these cases constitute the basal cell. Myoepithelial cell, neoplasm, salivary gland tumor. Myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary glands. The four patients with myoepithelial carcinoma two men and two women ranged in age from 48 to 64 years. They are preponderantly tumors of the parotid glands with a relatively low mortality but a decided locoregional aggressiveness. Four cases of epithelialmyoepithelial carcinoma of the salivary glands arose as painless masses in patients over 60 years old, three in the parotid and one in the submandibular gland. Apr 23, 2015 myoepithelial cells mecs are considered to be a key participant in most salivary gland diseases, particularly tumors. The acini of salivary glands are connected to hollow tubular structures which are called salivary ducts.
Solid nonmyxoid, myxoid pleomorphic adenomalike, reticular canalicularlike or mixed patterns of myoepithelial cells with no ductal differentiation plasmacytoid cells, spindle cells, clear cells, epithelioid cells, oncocytic cells, hyaline cells. Neoplastically modified myoepithelial cells are also generally accepted to be a significant component of salivary gland tumors such as epithelial. Review and updates of immunohistochemistry in selected. Apoptosis and proliferation of myoepithelial cells in. Salivary glands are essential structures in the oral cavity. This tumour may be particularly locally aggressive, but its clinical and biological features are not yet fully understood. Secretions from glands are expelled by the contractile function of myoepithelial cells. To investigate the lineage potential of k5expressing intercalated duct cells, we crossed the krt5 creer mouse, carrying a tamoxifeninducible cre recombinase creer, with the r26 tdtomato reporter strain.
Tamarin, in 1966, described such cells instead of glands as like an octopus sitting on a rock. It is composed of an array of tissue types, of both epithelial and mesen chymal origins, and is regarded as benign in clinical be havior, but has the potential to undergo malignant trans formation. Primary myoepithelial carcinoma of palate world journal. Myoepithelial carcinoma an overview sciencedirect topics. Cytology of myoepithelial carcinoma of the salivary gland. Myoepithelial carcinomas are described as the malignant version of benign myoepitheliomas. For most of these, the original diagnosis was malignant mixed tumor. The inner cells were epithelial and the outer cells myoepithelial, the latter. Solid nonmyxoid, myxoid pleomorphic adenomalike, reticular canalicularlike or mixed patterns of myoepithelial cells with no ductal differentiation plasmacytoid cells, spindle cells, clear cells, epithelioid cells, oncocytic cells, hyaline cells mucoid or hyaline stroma, rarely lipomatous rarely synchronous with adenoid cystic carcinoma. It is observed in a wide age category of children and adults. Salivary glands are composed mainly of parenchymal cells acini and myoepithelial cells mecs. Three cases arose from the parotid gland, and the remaining case was a recurrent tumor in the minor salivary glands of the hard palate.
A salivary gland can consist of a varied mixture of these types of end pieces. Twentythree neoplasms arising in major and minor salivary glands have been found to be composed of two types of myoepithelial cells the plasmacytoid and spindle cell form. It is concluded that the myoepithelial cells of the salivary glands are supplied with a parasympathetic motor innervation which can cause them to contract. The full expression of both morphogenesis and secretory cell differentiation in salivary glands is modulated or controlled, at least in part, by interactions between the salivary epithelium and. It comprises approximately 1 to 2% of salivary gland neoplasms 1,2,3. A 54yearold woman presented with an abnormal lung shadow on a. Histologically, all the tumours were composed of small ducts with a double cell lining surrounded by a basement membrane. Subsequently the tumour recurred twice and was characterised by invasion of the mandible. 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. They also act as tumor suppressor and are considered very. They are specialized cells capable of contraction aiding in the expulsion of saliva. Rare benign tumor composed only of myoepithelial cells. This clinically oriented book provides a comprehensive update on the biology, diagnosis, and treatment of salivary gland cancer. Epithelial myoepithelial carcinoma emc of salivary gland is a malignant epithelial tumor, composed of two distinct cell types, affecting either the major or minor salivary glands.
They are interposed between the secretory cells and the basal lamina. Nov 18, 2016 myoepithelial carcinoma is a rare malignant cancerous tumor that usually occurs in the salivary glands in the mouth, but can also occur in skin and soft tissues. They are present in salivary glands, mammary gland, sweat gland and lacrimal gland. These may be positive for alpha smooth muscle actin and can contract and expel the secretions of exocrine glands. The histological and immunohistochemical evidence of squamous metaplasia from myoepithelial cells in the breast. Myoepithelial cells are smooth muscle like cells having epithelial origin.
Detailed information is presented on molecular characterization and radiological staging, and a series of treatmentrelated chapters describe the different surgical approaches to major and minor salivary gland cancer, including reconstructive surgery techniques, and. Myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary. Pathophysiology of myoepithelial cells in salivary glands ncbi. In the terminal portion of the salivary glands, myoepithelial cells embrace the acini. Diagnostic dilemmas caused are due to inadequacy of characterizing. To date, no definitive therapeutic approach can compensate the impairment of salivary glands, and treatment are purely symptomatic.
Know the localization of myoepithelial cells and nerves in relation to the acinar cells, and their role in secretory functions. Mar 01, 2015 myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary glands. Myoepitheliomas are tumors arising from myoepithelial cells mainly or exclusively. Because of its rarity and unproven malignant potential, the optimal therapy for pemc has not been defined.
In addition, 10 cases of myoepithelial carcinomas devoid of clear cell change and 12 cases of benign myoepithelioma were included as well. In addition, myoepithelial cells surround the end piece, their function being to assist in propelling. Pathophysiology of myoepithelial cells in salivary glands amisha ashok kumar shah, aamera farouq mulla, mrinal mayank department of oral pathology and microbiology, m. Dual innervation can be found in myoepithelial cells, acinar endpieces and local blood vessels, all of which plays a functional role in salivary gland secretion 34. Limited regeneration of adult salivary glands after severe. In developing muscle, the mesothelium also develops deep invaginations, which penetrate far into the underlying connective tissue and then detach from the epithelium covering the surface of the rudiment to form blind cavities delimited by epithelial cells, which later differentiate into myoepithelial cells dolmatov and ivantey, 1993. Epithelial and myoepithelial cells positive for respective markers gfap negative basal cell adenoma 21. They can be routinely identified in many normal tissues that have secretory functions, such as the major and minor salivary glands, lacrimal glands, sweat glands, breasts, and the prostate. Salivary duct carcinoma mucoepidermoid carcinoma incidence most common malignant salivary gland tumor children and adults major and minor salivary glands p k i id 5th t 6th d d 36 peak incidence 5th to 6th decades clinical mass lesion surgical treatment with margins.
Pathophysiology of myoepithelial cells in salivary glands. In salivary glands, the myoepithelial cells that surround the intercalated ducts are spindled in contrast to the large stellate ones that envelop the acini. 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%. Primary salivary clear cell tumors a diagnostic approach. Read innervation and myoepithelial arrangements in the submandibular salivary gland of ferret investigated by enzyme, catecholamine and filament histochemistry, archives of oral biology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Myoepithelial cells mecs are one of the nonsecretory components of salivary gland acini. Myoepithelial carcinoma can arise in both minor and major salivary glands but with a predilection for the parotid gland. Metastatic tumors such as renal cell carcinoma or balloon cell melanoma are also a consideration.
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