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Journal of Pharmacy & Bioallied Sciences Aug 2015Myoepithelioma is a benign salivary gland tumor in the head and neck region, accounting for 1-1.5% of all glandular tumors. The diagnosis is rendered...
Myoepithelioma is a benign salivary gland tumor in the head and neck region, accounting for 1-1.5% of all glandular 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). In our case report, this lesion has occurred in a 46-year-old female patient, and presented as well defined, nodular growth on the right posterior palatal region. Bony erosion and invasion were observed radiographically, and the lesion was excised surgically, with 1-2 cm of clear margin. The microscopic features included proliferating tumor sheets, composed of bland looking spindle and plasmacytoid shaped myoepithelial cells, and few cells showed clear cytoplasm, which were confirmed immunohistochemically as myoepithelial cells. Thus, the final diagnosis of benign myoepithelioma was rendered and no recurrence had been reported so far in the regular follow-up.
PubMed: 26538968
DOI: 10.4103/0975-7406.163560 -
Journal of Dental Sciences Mar 2017Myoepithelioma is a rare form of salivary gland tumor composed entirely of myoepithelial cells. This tumor was formerly considered to be a subtype of pleomorphic...
Myoepithelioma is a rare form of salivary gland tumor composed entirely of myoepithelial cells. This tumor was formerly considered to be a subtype of pleomorphic adenoma; however, in the 1991 World Health Organization classification, it is listed as an independent entity. The most favorable site of occurrence of myoepithelioma is the parotid gland. Here, we report an extremely rare case of myoepithelioma of the upper lip. A 56-year-old woman presented with a painless mass on her upper lip. Magnetic resonance imaging revealed a 23 mm × 18 mm well-defined ovoid tumor. A benign minor salivary gland tumor was clinically suspected, and the patient underwent complete resection of the tumor under general anesthesia. The tumor was histopathologically diagnosed as a benign myoepithelioma of the minor salivary gland. Immunohistochemically, the tumor cells were positive for S-100 protein, AE1/AE3, CAM5.2, CK7, vimentin, and calponin, confirming the morphologic diagnosis of myoepithelioma. The patient's postoperative clinical course was uneventful, and satisfactory results were obtained both functionally and esthetically. To the best of our knowledge, this is the sixth case of myoepithelioma of the upper lip reported in English-language research.
PubMed: 30895031
DOI: 10.1016/j.jds.2013.02.020 -
Indian Journal of Otolaryngology and... Dec 2022Tumors of the salivary glands are rare and have various histo-pathological subtypes. The overall incidence is 2.5-3 per 100,000 patients per year. Myoepithelioma of the...
Tumors of the salivary glands are rare and have various histo-pathological subtypes. The overall incidence is 2.5-3 per 100,000 patients per year. Myoepithelioma of the parotid gland is very rare with an incidence of only 1-1.5% among all salivary gland tumors. The diagnostic criteria for benign myoepithelioma were laid down on the basis of the work of Barnes and Sciubba. A 30-year-old lady presented to our university with a mass slowly increasing in size. There were no aggravating and/or relieving factors found. On examination a 3 × 3 cm diffuse swelling was found around the right pre auricular area. Fine Needle Aspiration Cytology (FNAC) was performed. The findings were suggestive of a pleomorphic adenoma. The patient underwent a right sided superficial parotidectomy to remove the tumor. The final histopathology report revealed the tumor to be a myoepithelioma. Myoepithelioma is a benign salivary gland neoplasm formed almost entirely of myoepithelial cells arranged in a sheet, island or cord-like fashion. On CT scans, it presents as a well-circumscribed homogenous lesion with lobulated or smooth margins. Myoepitheliomas may also have nodules that enhance under contrast and areas of linear bands that do not. The recommended treatment for a myoepithelioma is complete surgical excision with wide margins. It has a very low recurrence rate compared to the 15-18% recurrence rate for pleomorphic adenomas. Utilization of immunohistochemical staining is of utmost importance in suspected myoepithelioma cases to ensure proper treatment and follow-up. Myoepitheliomas are rare tumors which must be included in the differential if a patient presents with a tumor of characteristics similar to those described above. Immunohistochemistry and electron microscopy are useful tools for the diagnosis of myoepitheliomas.
PubMed: 36742563
DOI: 10.1007/s12070-021-02763-x -
Neurology India 2019Intracranial myoepithelial tumors are extremely rare with <10 cases reported outside the sellar region. The authors describe a case of a 43-year-old male patient who... (Review)
Review
Intracranial myoepithelial tumors are extremely rare with <10 cases reported outside the sellar region. The authors describe a case of a 43-year-old male patient who presented with headache, numbness in the face, and a dumbbell-shaped lesion in the Meckel's cave clinically and radiologically suggestive of a Schwannoma. The histopathological and immunohistochemical evaluation led to a diagnosis of myoepithelioma. A review of literature reveals that this is only the ninth case of intracranial myoepithelial tumor reported, fifth benign case, and the first to be reported in the Meckel's cave region.
Topics: Adult; Brain Neoplasms; Humans; Male; Myoepithelioma
PubMed: 31744974
DOI: 10.4103/0028-3886.271273 -
Head and Neck Pathology Sep 2022Pleomorphic adenoma (PA) is the most common biphasic type of salivary gland tumour to arise in adults. It is a biphasic tumour composed of both luminal (ductal) cells...
Pleomorphic adenoma (PA) is the most common biphasic type of salivary gland tumour to arise in adults. It is a biphasic tumour composed of both luminal (ductal) cells and abluminal (basal and myoepithelial) cells. Other biphasic salivary gland type tumours, both benign and malignant, can mimic PA, especially on small biopsies. Previous studies have shown that glial fibrillary acidic protein (GFAP) is preferentially expressed in PA and can be useful in the distinction from other salivary gland tumours. However, most of these studies were performed on a small subset of tumour types at a time when the classification of salivary gland type tumours was less refined. The purpose of this study was to assess the expression of glial fibrillary acidic protein (GFAP) in a broad group of both benign and malignant salivary gland tumours. The expression of GFAP was assessed in 99 tumours including 54 PAs, 5 basal cell adenomas, 1 myoepitheliomas, 5 adenoid cystic carcinomas, 6 epithelial-myoepithelial carcinomas (EMCA), 6 mucoepidermoid carcinomas, 7 salivary duct carcinomas, 1 adenocarcinomas NOS, 2 myoepithelial carcinomas, 4 basal cell adenocarcinomas, 5 acinic cell carcinomas and 3 polymorphous adenocarcinomas. Of the malignant cases, 8 were classified as carcinomas ex PA. GFAP was also assessed in 19 concurrent biopsy specimens. GFAP was expressed in the resections of 51 PAs examined (94%). Expression was predominantly strong and diffusely seen in myoepithelial cells. Strong and diffuse GFAP expression was also seen in two EMCAs (33%) and one myoepithelial carcinoma (50%). On biopsy specimens, 100% of PAs and basal cell adenomas expressed GFAP. GFAP was also seen in 1 out of 3 carcinomas ex PAs on biopsies. Almost all PAs show strong and diffuse expression of GFAP. In contrast, most malignant neoplasms that can mimic PA on biopsies show only rare, focal expression. Other benign tumours composed of abluminal/myoepithelial cells also show focal expression of GFAP, highlighting the spectrum these tumours share with PA. Overall, the presence of strong and diffuse GFAP expression can favour a benign neoplasm, specifically a PA, on limited biopsy specimens.
Topics: Adenoma; Adenoma, Pleomorphic; Adult; Biomarkers, Tumor; Carcinoma; Carcinoma, Acinar Cell; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Myoepithelioma; Salivary Gland Neoplasms
PubMed: 35064902
DOI: 10.1007/s12105-021-01409-2 -
International Journal of Oral Science Sep 2023Pleomorphic adenoma (PA) is the most common benign tumour in the salivary gland and has high morphological complexity. However, the origin and intratumoral heterogeneity...
Pleomorphic adenoma (PA) is the most common benign tumour in the salivary gland and has high morphological complexity. However, the origin and intratumoral heterogeneity of PA are largely unknown. Here, we constructed a comprehensive atlas of PA at single-cell resolution and showed that PA exhibited five tumour subpopulations, three recapitulating the epithelial states of the normal parotid gland, and two PA-specific epithelial cell (PASE) populations unique to tumours. Then, six subgroups of PASE cells were identified, which varied in epithelium, bone, immune, metabolism, stemness and cell cycle signatures. Moreover, we revealed that CD36 myoepithelial cells were the tumour-initiating cells (TICs) in PA, and were dominated by the PI3K-AKT pathway. Targeting the PI3K-AKT pathway significantly inhibited CD36 myoepithelial cell-derived tumour spheres and the growth of PA organoids. Our results provide new insights into the diversity and origin of PA, offering an important clinical implication for targeting the PI3K-AKT signalling pathway in PA treatment.
Topics: Humans; Adenoma, Pleomorphic; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Transcriptome; Myoepithelioma
PubMed: 37679344
DOI: 10.1038/s41368-023-00243-2 -
Head and Neck Pathology Mar 2023Myoepithelial neoplasms of the salivary gland are benign or malignant neoplasms composed exclusively of neoplastic myoepithelial cells. These tumors, including the... (Review)
Review
BACKGROUND
Myoepithelial neoplasms of the salivary gland are benign or malignant neoplasms composed exclusively of neoplastic myoepithelial cells. These tumors, including the benign myoepithelioma and the malignant counterpart myoepithelial carcinoma, exhibit a wide range of cytomorphologic features and architectural patterns.
METHODS
Review.
RESULTS
Myoepithelial cells can be epithelial, plasmacytoid, clear cell, spindle cell, and/or oncocytic cell, arranging as trabeculae, solid sheets, nests, cords, and/or single cells. A stromal component is commonly but not universally present, Therefore, their differential diagnoses are quite broad, including salivary gland neoplasms especially those with a myoepithelial component, plasmacytoma, melanoma, and various mesenchymal tumors.
CONCLUSION
In this review, we summarize the characteristic histologic features, useful immunohistochemical panel, and common molecular alterations of myoepithelial tumors and their top differential diagnoses. A logical stepwise algorithmic approach and an immunohistochemical panel to include multiple myoepithelial markers are essential to establish the correct diagnosis.
Topics: Humans; Biomarkers, Tumor; Immunohistochemistry; Salivary Gland Neoplasms; Salivary Glands; Myoepithelioma; Carcinoma
PubMed: 36928733
DOI: 10.1007/s12105-022-01502-0 -
Head and Neck Pathology Mar 2015Myoepithelial tumors in skin and soft tissue are uncommon but have been increasingly characterized over the past decade. Men and women are equally affected across all... (Review)
Review
Myoepithelial tumors in skin and soft tissue are uncommon but have been increasingly characterized over the past decade. Men and women are equally affected across all age groups and lesions arise most frequently on the extremities and limb girdles. Approximately 20 % of cases occur in pediatric patients, in whom they are frequently malignant. Similar to their salivary gland counterparts, myoepithelial tumors of soft tissue demonstrate heterogeneous morphologic and immunophenotypic features. Tumors are classified as mixed tumor/chondroid syringoma, myoepithelioma, and myoepithelial carcinoma; in soft tissue, tumors having at least moderate cytologic atypia are classified as malignant. Mixed tumor and myoepithelioma show a benign clinical course, with recurrence in up to 20 % (typically secondary to incomplete excision), and do not metastasize. In contrast, myoepithelial carcinoma shows more aggressive behavior with recurrence and metastasis in up to 40-50 % of cases. The majority of myoepithelial neoplasms typically coexpress epithelial antigens (cytokeratin and/or EMA) and S-100 protein; GFAP and p63 are frequently positive and a subset of malignant neoplasms lose INI1 expression. Up to 45 % of myoepitheliomas and myoepithelial carcinomas harbor EWSR1 gene rearrangements, unlike mixed tumor/chondroid syringoma which is characterized by PLAG1 gene rearrangement. While mixed tumor/chondroid syringoma are likely related to primary salivary myoepithelial tumors, soft tissue myoepithelioma and myoepithelial carcinoma appear to be pathologically distinct neoplasms.
Topics: Female; Humans; Immunophenotyping; Male; Myoepithelioma; Soft Tissue Neoplasms
PubMed: 25804378
DOI: 10.1007/s12105-015-0618-0 -
Indian Journal of Otolaryngology and... Oct 2022Salivary gland neoplasms pose considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types...
Salivary gland neoplasms pose considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types and variants & similar histological features with other tumor entities. Myoepithelial and basal cells play a significant role in the pathogenesis of salivary gland neoplasm. p63 and smooth muscle actin are more reliable markers for identifying these cells and not studied much comparing their reliability in the diagnosis of salivary gland neoplasms. Hence, the aim of this study is to evaluate and compare the diagnostic reliability of immunohistochemical markers such as p63 and smooth muscle actin (SMA) in the diagnosis of various benign and malignant salivary gland neoplasms. The study comprises of 18 samples categorized into two groups: Group I comprised 9 cases, of which 4 cases were Pleomorphic adenoma, 2 cases were Myoepithelioma, 2 cases of Basal cell adenoma and 1 case was Warthin's tumor; and Group II consisted of 9cases, of which 3 was Mucoepidermoid carcinoma, 1 cases were Myoepithelial carcinoma and 5 cases were Adenoid cystic carcinoma. The selected cases were subjected to immunohistochemistry (IHC) procedure to assess the expression pattern of p63 and smooth muscle actin. The obtained data was analysed statistically by using Mann-Whitney test. In SMA, strong positivity for epithelial and connective tissue components of benign salivary neoplasm is about 22.2%respectively. In malignant salivary neoplasm, SMA was strongly positive for the epithelial and connective tissue component of about 77.7% and 88.8% cases respectively. The difference in the connective tissue components was found to be statistically significant ( = 24, = 0.032). P63 was strongly positive for the epithelial and connective tissue component of benign salivary neoplasm of about 33.3% and 11.1% cases respectively.In malignant salivary neoplasm, p63 was strongly positive for the epithelial component of about 66.6% cases and connective tissue is completely negative. Alpha-SMA can be utilized as reliable IHC markers for salivary gland neoplasms due to its diagnostic importance in tumors with myoepithelial origin indicative of the histogenesis of salivary gland tumors and even p63 can be used as specific markers for differentiation of malignant salivary gland tumors.
PubMed: 36452668
DOI: 10.1007/s12070-020-02237-6