Basaloid tumors are a common diagnostic problem in salivary gland pathology. Myoepithelial cells sometimes referred to as myoepithelium are cells usually found in glandular epithelium as a thin layer above the basement. Myoepithelioma is usually a benign tumor arising from neoplastic myoepithelial or basket cells which are found between the basement membrane and the basal. Pathophysiology of myoepithelial cells in salivary glands ncbi. Discussion the benign myoepithelioma of salivary gland is a rare neoplasia of myoepithelial nature, made up of. 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. Mec generally arises from the parotid gland 2982 % of all cases and rarely from the submandibular gland, minor salivary glands, or the upper respiratory tract 24.
Myoepithelial tumors adenomyoepithelioma adenoid cystic carcinoma mec rich idc. The origin of salivary gland tumors could be from acinarductal epithelial cells luminal cells andor. Cutaneous myoepithelial carcinoma with disseminated. Myoepithelial tumours of the salivary glands current diagnostic.
Myoepithelial cells mecs are considered to be a key participant in most salivary gland diseases, particularly tumors. Myoepithelial cells are the main component in pleomorphic. Myoepitheliomas mostly occur in salivary glands, as well as in breast, skin, and lung. Lg epithelium is composed of ductal, acinar, and myoepithelial cells mecs bordering the basal lamina and separating the epithelial layer from the extracellular matrix. Mecs play an important role in supporting the morphogenesis, differentiation and polarization of salivary acini. For most of these, the original diagnosis was malignant mixed tumor. Ying and beronja employ lentiviral targeting and quantitative lineage tracing of murine mammary epithelium to establish that early progenitors are bipotent and with equal longterm growth potential. Diagnostic dilemmas caused are due to inadequacy of characterizing the wide spectrum of morphologic and immunologic features which are different for both. Review of myoepithelial cells in health and in tumours. Myoepithelial cell, neoplasm, salivary gland tumor. Table 2 lists the immunoreactions for the analyzed myoepithelioma antibodies. This is most apparent in pleomorphic adenoma, where the outer layers of twotiered epithelial cells show no or variable. Myoepitheliomas are tumors arising from myoepithelial cells mainly or exclusively. Get detailed information about the treatment for newly diagnosed and recurrent salivary gland cancer in this summary for clinicians.
Myoepithelial cell carcinoma is a rare malignant neoplasm. Tumors mostly involve the major salivary glands, 42. Nests, cords and sheets of epithelioid, clear, spindle or plasmacytoid cells in hyalinized or chondromyxoid stroma epithelioid cells predominate in 93% of childhood cases moderate to severe atypia due to coarse chromatin, prominent nucleoli, nuclear pleomorphism variable mitotic rate median 8 10 hpf often tumor necrosis. Combined myoepithelial carcinoma and myoepithelioma in. Only 1% of all salivary gland neoplasms are myoepitheliomas. However, few studies were published on the expression of p63 in salivary gland tumors 1417. They are present in the sweat glands, mammary glands, lacrimal glands and in salivary glands. Approximately 66% of these tumors occur in a part of the salivary gland, known as the parotid gland. Histologic evaluation of myoepithelial participation in. It can be present in individuals of a wide age range including children and adults. These are characterized by high expression of actin and myosin myofilaments in their cytoplasm, which make their contractility one of their main functions. The importance of being a myoepithelial cell breast. Myoepithelial cells are a normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement membrane. Invasive myoepithelial carcinoma ex pleomorphic adenoma of.
They are interposed between the secretory cells and the basal lamina. Myoepithelial cells are an important component of salivary gland tumors and are partly responsible for their diverse histology. Mc usually presents as a slowgrowing painless mass arising in the parotid gland, but may involve other salivary glands. Myoepithelial cells in pathology pubmed central pmc. About 60% to 70% of mca develop in a benign mixed tumor. Current perspectives in salivary gland tumors c pramod redder 1, v suresh kandagal 1, nupura vibhute 1, pramod s ingaleshwar 2, sharan j shetty 2, sameer ahamad 3 1 department of oral pathology and microbiology, school of dental sciences, krishna institute of medical sciences university, karad, maharashtra, india 2 department of oral pathology and microbiology, a. However, in some tumors, hybrid tumor cell forms are present along with typical basal andor.
In this tissue, the myoepithelial cells showed markers for asma and ck 14. Myoepithelial cell markers in salivary gland neoplasms. Myoepithelium in pleomorphic adenomas myoepithelial cells are the main component in pleomorphic adenomas. Embryonic barcoding of equipotent mammary progenitors. Myoepithelial cellrich pleormorphic adenoma of minor. They are found in the sweat glands, mammary glands, lacrimal glands, and salivary glands. Primary myoepithelial carcinoma of palate world journal. Effects of benzodiazepines on acinar and myoepithelial cells. We now need to understand more about their origin and to reconsider their place in the complex process of mammary morphogenesis. Myoepithelial carcinoma mec is a rare salivary gland tumor, accounting for 0.
Collina g, gale n, visona a, betts cm, cenacchi v, eusebi v. Actin versus vimentin in myoepithelial cells of salivary. These may be positive for alpha smooth muscle actin and can contract and expel the secretions of exocrine glands. Pathophysiology of myoepithelial cells in salivary glands. Cutaneous myoepithelial carcinoma is a tumor that can occasionally show ewsr1 gene rearrangement. Myoepithelioma of salivary gland is an uncommon benign tumor typically arising in. Narrowed ducts in hyaline stroma with a solid growth pattern. The cystic lesion has a mildly fibrotic appearing wall, is lined by histiocytes intermixed with rare lymphocytes, and contains mucous and macrophages. The relatively recently recognized and rarely encountered malignant myoepithelial tumor ie, myoepithelial carcinoma was first described by stromeyer et al 11 in 1975 and has been included in the world health organization classification of salivary gland tumors since 1991. Myoepithelial cell markers in salivary gland neoplasms article in international journal of surgical pathology 1. Myoepithelial tumours of the salivary glands current. It is noteworthy that myoepithelial cells of the salivary glands are located between the basal layer and plasmatic membrane of the secretory acinar cells and interspersed ducts klein, 2002.
He x100 discussion epithelial myoepithelial carcinoma represents 1% of all salivary gland tumors. Histologic evaluation of myoepithelial participation in salivary gland tumors. A report of two cases the two illustrative examples are of small glandular proliferations in the breast that show complete loss of expression in one, and focal loss in the other, of myoepithelial cell markers. The sections show a stratified squamous epithelium with a thin layer of parakeratosis, minor salivary glands, and a wellcircumscribed cystic lesion. Studies have shown that the antip63 antibody is an effective marker of myoepithelial cells with higher specificity. This tumour may be particularly locally aggressive, but its clinical and biological features are not yet fully understood. Salivary gland myoepithelial carcinoma mc or malignant myoepithelioma is a rare entity. Detection of myoepithelial differentiation both in aspiration cytology and histologic examination can also help diagnosing a tumor as of salivary gland type. Wehavefoundonly onecase fromthe united kingdomdescribed 419 as epithelialmyoepithelial carcinoma,12 although the parotid clear cell adenoma reported by corridan in 1956 was almost certainlyanother. Myoepithelial neoplasms represent a heterogenous group of tumors of which classification is incomplete and evolving. To the best of our knowledge, such an association has never been. The mammary myoepithelial cell was named the cinderella of mammary cell biology in light of the earlier focus on the luminal cell.
It has been described previously in head and neck sites such as buccal mucosa, alveolar ridge, and. Using these insights, they design a largescale genetic screen that can identify functional drivers of tumor initiation and subtype shift in breast cancer. 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. They can be recognized with various immunohistochemical markers, although none is specific or reliable in every case. Cutaneous myoepithelial carcinoma is a rare malignant adnexal neoplasm with metastatic potential that can present in the skin. Current concepts in diagnosis of unusual salivary gland tumors. They were incorporated into the world health organization classification of soft tissue tumors in 2002. Myoepithelial cells clinical cancer investigation journal. Here we present an exceptional case of myoepithelial carcinoma and myoepithelioma association. An epithelial myoepithelial carcinoma in parotid gland. 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. Thirteen men and 12 women aged 24 to 77 years mean age, 55 yrs participated in the study, and most presented with a painless mass. Diagnostic dilemmas caused are due to inadequacy of characterizing. The topic benign myoepithelial tumor of salivary gland you are seeking is a synonym, or alternative name, or is closely related to the medical condition myoepithelioma of salivary gland.
Salivary gland tumors are relatively uncommon and account for approximately 36% of all neoplasms of the head and neck. Plga is currently a topic of controversy and beyond the scope of. Myoepithelial cells are usually found in glandular epithelium as a thin layer above the basement membrane but normally beneath the luminal cells. Myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary glands. Myoepithelial cells can be detected by several immunohistochemical markers elias, 2015. Excision with negative margins and close followup is recommended for cutaneous myoepithelial carcinoma.
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. Mature mecs have contractile ability and morphologically resemble smooth muscle cells. Mecs structurally resemble both epithelial cells and smooth muscles. Neoplastic myoepithelial cells in both benign and malignant tumours can take several forms, including epithelioid. Myoepithelial cells are stellateshaped and also known as basket cells. Myoepithelial cell definition of myoepithelial cell by. Soft tissue myoepithelial carcinoma and myoepithelioma are rare entities, part of myoepithelial tumors. Epithelialmyoepithelial carcinoma of the parotid gland. Lacrimal gland lg is an exocrine tubuloacinar gland that secretes the aqueous layer of the tear film. Myoepithelial cells are ectodermally derived contractile cells that act as smooth muscle cells. Salivary gland myoepithelial carcinoma springerlink. Myoepithelial cells mecs are one of the nonsecretory components of salivary gland acini.
Mammary myoepithelial cells have recently been described as natural tumour suppressors. Myoepithelial cells mec of the salivary glands in health and. Salivary gland cancer treatment options include surgery with or without postoperative radiation therapy, radiation therapy, and chemotherapy. Myoepithelioma of salivary gland is an uncommon benign tumor typically arising in the major salivary glands. Immune marking for ck 14 was detected in ductal cells. Myoepithelial cell carcinoma is a rare malignant neoplasm of salivary gland origin that typically presents in the parotid gland and minor salivary glands.
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