Myoepithelioma occurs in most major and minor salivary gland tissues, and it is generally a biologically benign lesion. Myoepithelioma me is a benign salivary gland tumor composed almost exclusively of sheets, islands, or cords of cells with myoepitheliomal differentiation. Myoepitheliomas are rare, benign neoplasms affecting predominantly parotid gland and to a lesser extent minor salivary glands. The histological appearance includes solid, myxoid and reticular growth patterns. Myoepithelioma is a benign salivary gland tumor in the head and neck region, accounting for 11. Rare benign tumor composed only of myoepithelial cells. They most commonly affect the major and minor salivary glands with the parotid gland being the most common, approximately 40%. A final diagnosis of salivary gland myoepithelioma with focal capsular invasion was made, and the case was regarded as a myoepithelial tumor of uncertain malignant potential. Cutaneous myoepithelial carcinoma is a rare malignant adnexal neoplasm with metastatic potential that can present in the skin.
Histological examination of the second recurrence showed a malignant spindle cell. Mc usually presents as a slowgrowing painless mass arising in the parotid gland, but may involve other salivary glands. Jul 11, 2008 myoepithelioma is a rare benign neoplasm. The diagnosis was made on the basis of characteristic ultrastructural as well as immunohistochemical findings. Myoepithelioma are uncommon, representing approximately 1% of salivary gland tumors. Myoepithelioma of minor salivary glands a diagnostic challenge. This tumour may be particularly locally aggressive, but its clinical and biological features are not yet fully understood.
The lesions were clinically suspected to be epidermal cyst. 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. The topic malignant myoepithelioma of salivary gland you are seeking is a synonym, or alternative name, or is closely related to the medical condition myoepithelial carcinoma of salivary gland. Plasmacytoid myoepithelioma of minor salivary glands. Salivary gland myoepithelioma with focal capsular invasion. Clinically it resembles like other tumour masses and thus posed challenge to clinician and pathologist. These tumors consisted of spindle cells that exhibited an arrangement similar to leiomyoma or fibroma. It was once considered to be a type of pleomorphic adenoma pa, but myoepitheliomas are today believed to be relatively aggressive tumors. Pure accounting for less than 1% of all salivary gland tumors. We report two patients with myoepithelioma of parotid gland presenting as infra.
Pdf spindle cell myoepithelioma of the parotid gland. Myoepitheliomas of minor salivary glands accounts to only 1. Myoepithelioma is a rare neoplasm of the salivary glands, generally occurring in the parotid gland and less often in the minor accessory salivary gland. Excision with negative margins and close followup is recommended for cutaneous myoepithelial carcinoma. The diagnosis is rendered histopathologically, and it includes the.
Myoepithelioma is a rare neoplasm that accounts for fewer than 1% of all salivary gland tumors. Myoepitheliomas are rare salivary gland tumours which make up between 1 and 1. Only a few case reports describing ct imaging features of me have been published. Classically, they are found in the parotid gland or palate. Only 1% of all salivary gland neoplasms are myoepitheliomas. It is a benign salivary gland tumor that consists entirely of myoepithelial cells with variable cellular morphologies including spindle, epithelioid, plasmacytoid, or clear cells.
It is a benign tumor that is composed almost exclusively of myoepithelial cells. Oncocytic myoepithelioma and pleomorphic adenoma of the. To the best of our knowledge, such an association has never been reported in the literature. Historically, they were initially classed as a subtype of pleomorphic adenoma, but were recognised as a separate tumour class by the world health organisation in. Subsequently the tumour recurred twice and was characterised by invasion of the mandible. Approximately 66% of these tumors occur in a part of the salivary gland, known as the parotid gland. Myoepithelioma is uncommon and account for only 1% of all salivary gland tumours. Maria della misericordia, 33100 udine, italy b department of oral pathology, faculty of medicine, university of. Revised who histological classification of salivary gland tumours 171. Myoepithelioma of parotid gland presenting as infra. Myoepithelioma of salivary glands are very rare, accounting. Salivary gland myoepithelial carcinoma springerlink. Myoepithelioma is a wellcircumscribed or encapsulated tumor. Myoepithelioma is a benign tumor of the oral cavity, arising predominantly from major and minor salivary glands, and accounting for 11.
Only three cases of sinonasal myoepithelioma have been reported in the literature. Patients a total of 51 patients with myoepithelialrich. Myoepitheliomas are most common in young adults between the ages of 30 and 50 and there are very few cases reported in. These tumors can occur in most of the glandular structures like salivary glands, breast and sweat glands of the skin.
Mc may arise from preexisting benign lesions, such as. Myoepithelioma of a minor salivary gland of the cheek. They were incorporated into the world health organization classification of soft tissue tumors in 2002. Myoepithelioma is usually a benign tumor arising from neoplastic myoepithelial or basket cells which are found between the basement membrane and the basal. Combined myoepithelial carcinoma and myoepithelioma in soft. Malignant myoepithelioma mme of the salivary gland, also known as myoepithelial carcinoma, is rare and its biologic. It differs from the pleomorphic adenoma because it does not bear any ductal component5.
Pdf myoepithelioma of minor salivary glands a diagnostic. Myoepithelioma was recognized as a histologically distinct entity by the world health organization who in 1991. A myoepithelial carcinoma, a rare malignant salivary gland neoplasm, arose in a pleomorphic adenoma of the parotid gland. We describe some unusual histological features associated with onococytic metaplasia in benign myoepithelial cellderived salivary gland tumours, hoping to help to avoid the overdiagnosis of malignancy. Capsules are generally better developed in tumors of the major glands, whereas those arising in the palate or other minor salivary or seromucinous gland sites are circumscribed but not usually encapsulated.
Objective to analyze the importance of unique cytoarchitectural patterns and the immunohistochemical profile in the diagnosis of myoepithelial carcinomas. Myoepitheliomas of the salivary gland are very rare tumors, with an incidence of less than 1% of all salivary gland tumors. The most common site of involvement is parotid gland, followed by palate in the oral cavity. Mar 18, 2015 myoepithelioma was recognized as a histologically distinct entity by the world health organization who in 1991. Myoepithelioma of salivary gland is an uncommon benign tumor typically arising in the major salivary glands. About 60% to 70% of mca develop in a benign mixed tumor. The vast majority are benign, with only rare malignant examples reported in the literature. A similar tumor type may be found in the tongue, referred to as ectomesenchymal chondromyxoid tumor. As the name suggests, it consists of myoepithelial cells.
Mar 27, 2018 myoepithelioma of salivary gland is an uncommon benign tumor typically arising in the major salivary glands. The number of case reports is increasing as pathologists have become more aware. Myoepithelioma is a rare neoplasm of the salivary glands, generally occurring in the parotid gland and less often in the minor accessory salivary gland of the oral. Cutaneous myoepithelial carcinoma with disseminated. Robiony a a department of maxillofacial surgery, faculty of medicine, university of udine, piazzale s. Myoepithelioma is a rare benign tumor of the salivary glands and is usually seen in the parotid gland and the minor salivary glands. It can be present in individuals of a wide age range including children and adults the cause of formation of salivary gland myoepithelioma is not wellunderstood, although certain chromosomal alterations and gene mutations have been. In this report, we discuss the histologic criteria required to diagnose malignancy in salivary gland myoepithelial tumors. The diagnosis is rendered histopathologically, and it includes the proliferation of myoepithelial cells, without chondroid or myxochondroid stroma and ductal components up to 5% of ductal component is acceptable. Myoepithelial carcinoma malignant myoepithelioma of the. Salivary gland myoepithelial carcinoma mc or malignant myoepithelioma is a rare entity. Myoepithelioma is usually a benign tumor arising from neoplastic myoepithelial or basket cells which are found between the basement membrane and the. The peak incidence is in the sixth and seventh decades.
Benign myoepitheliomas are mainly composed of myoepithelial cells, which are ectodermally derived cells located between the basal surface of acinar units, basement membrane, and surrounding intercalated duct. Myoepithelioma of the head and neck, also myoepithelioma, is a salivary gland tumour of the head and neck that is usually benign as the name suggests, it consists of myoepithelial cells. Diagnosis of myoepithelioma through light microscopy is possible and immunohistochemistry is done to facilitate the diagnosis. The 2 most common sites of occurrence are the parotid gland 40% and the. Article pdf available in journal of oral and maxillofacial pathology. Myoepithelioma of salivary glands is a rare neoplasm generally occurs in parotid glands and less often in minor salivary glands of the palate and oral cavity. Some authors believe that myoepithelial cells play a definite role in several salivary gland tumors, such as mixed tumors, adenoid cystic carcinomas, and salivary duct carcinomas. Sep 24, 2014 soft tissue myoepithelial carcinoma and myoepithelioma are rare entities, part of myoepithelial tumors. Myoepithelioma of minor salivary glands a diagnostic. They are most commonly found in the parotid gland and palatal area 1. Cutaneous myoepithelial carcinoma is a tumor that can occasionally show ewsr1 gene rearrangement. The tumors mostly present as asymptomatic, slowly progressive masses over a period of months to years in the patient with average age in the fourth decade 1.
Myoepithelioma is a rare and unusual salivary gland tumor that can be considered a monomorphic variant of pleomorphic adenoma. Since 1943 when sheldon identified them and characterized them as myoepithelioma, less than 100 cases have been reported in the literature. Myoepithelioma is rare benign neoplasm, usually involves salivary glands and very less often seen in minor salivary glands of nose. Jan, 2010 myoepithelial cells are usually seen between epithelial cells and basal cells in intercalated ducts and acini of exocrine glands. Myoepithelioma is a rare neoplasm of the salivary glands, generally occurring in the parotid gland and less often in the minor accessory salivary gland of the oral cavity. Dec 12, 2011 myoepithelioma is a rare benign tumor of the salivary glands and is usually seen in the parotid gland and the minor salivary glands. They most commonly affect the major and minor salivary glands with the parotid gland being. Most of these neoplasms arise in the parotid gland, and only a few occur in the submandibular or minor salivary glands. Here we present an exceptional case of myoepithelial carcinoma and myoepithelioma association.
Wed like to understand how you use our websites in order to improve them. Oncocytic change in myoepithelial cells in mes and pas can cause pitfalls in the differential diagnosis of salivary gland tumours. 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. Pdf malignant myoepithelioma of the salivary glands. It becomes very difficult to diagnose due to its varied presentation and propensity for malignant transformation. Myoepitheliomas of salivary glands are extremely rare, comprising approximately only 11. Such lesion shows a varied pattern of morphological growth, it may be solid, myxoid or reticular. Introduction myoepithelioma is defined as a benign tumour composed of myoepithelial cells. Such a rare case of myoepithelioma in salivary glands present at an unusual location around the left orbit is presented here. However, other rare sites like the lips, inner lining of the. Two cases of myoepithelioma occurring in the parotid gland were reported. Myoepithelioma have been described most commonly in salivary gland and accounts for 1% of all tumors developing in the salivary gland. The initial tumour was a pleomorphic adenoma with epithelial and myoepithelial elements.
The tumor cells of the two cases likewise contained myofilaments and gave a positive result for the s. Myoepithelioma is a benign salivary gland neoplasm, locally invasive and uncommon in children. Malignant myoepithelioma is a rare salivary gland carcinoma that might be confused with other neoplastic lesions, including carcinoma and sarcoma. Myoepithelioma is rare benign tumors representing about the 1% of all the salivary gland tumors. The aim of this study was to describe and characterize the ct findings of mes of the parotid. The tumor is composed exclusively of myoepithelial cells that show spindle, plasmacytoid, and clear cell morphology. Myoepithelioma of the parotid gland, pathology international. Myoepithelioma occurring in minor salivary glands of oral cavity accounts for 26% of all salivary gland myoepitheliomas and palate being the most common site 69. Myoepithelioma of the posterior oropharyngeal wall. It accounts for myoepithelioma and related lesions. Myoepithelial cells of ectodermal origin and mesodermal functionality, normal constituent cells of ductal structures in major and minor salivary glands and other organs, are modified cellular elements with both epithelial and myocontractile properties. Myoepithelioma of salivary glands are very rare, accounting for only 1%1. Myoepitheliomas are rare benign neoplasias of the salivary gland, more commonly found in the parotid1, 2, being. Pdf malignant myoepitheliomas myoepithelial carcinomas are uncommon, and we know of only 29 reported cases.
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