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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 Cytology Jan 2013Myoepithelioma of the breast is very rare. Breast myoepithelioma can develop in women from their early 20s right up to their 80s, but it is most common in women over 50....
Myoepithelioma of the breast is very rare. Breast myoepithelioma can develop in women from their early 20s right up to their 80s, but it is most common in women over 50. We report a case of 20-year-old female, who presented with a well-defined breast lump of 3 × 3 cm in size. Fine needle aspiration was performed. The cytological findings revealed good cellularity comprising monomorphic loosely cohesive sheets of plasmacytoid, round to polygonal cells with round to ovoid eccentrically placed nuclei, finely dispersed chromatin, and moderate amount of cytoplasm. On the basis of cytological findings, a diagnosis of benign myoepithelioma (plasmacytoid type) was made which was confirmed on histopathologic examination. The breast is a very rare localization for this type of tumor. The benign character of the disease in conjunction with its slow progression could delay its detection and diagnosis. A detailed pathology examination is a prerequisite for avoidance of misleading diagnosis.
PubMed: 23661946
DOI: 10.4103/0970-9371.107518 -
Head and Neck Pathology Jul 2013Myoepithelial neoplasms are tumors composed almost exclusively of cells with myoepithelial differentiation. They frequently contain spindle, plasmacytoid or epithelioid... (Review)
Review
Myoepithelial neoplasms are tumors composed almost exclusively of cells with myoepithelial differentiation. They frequently contain spindle, plasmacytoid or epithelioid shaped cells and may have oncocytic or clear cytoplasmic features. They are uncommon, accounting for 1.5 % of all salivary gland tumors and for 2.2-5.7 % of major and minor salivary gland tumors, respectively. Recently this author, together with several colleagues, have described three unusual myoepithelial tumors, two benign and one malignant that contained abundant intracellular mucin material, which they termed the mucinous variant of myoepithelioma. This represents a unique, previously undescribed subtype that does not fit in the current classification system. A literature review revealed several similar cases reported as "signet ring-cell" adenocarcinomas of salivary gland, which stained for myoepithelial markers, in addition to containing intracellular mucin material, that are more accurately classified as mucinous myoepithelioma. To date, there are 17 reported mucinous myoepitheliomas; four were classified as benign and 13 as malignant. Thirteen arose in minor salivary glands and four in the parotid gland. One patient presented with a lymph node metastasis. With minimal follow-up currently available, this appears to be a benign to low-grade malignancy.
Topics: Biomarkers, Tumor; Cystadenocarcinoma, Mucinous; Humans; Immunohistochemistry; Myoepithelioma; Salivary Gland Neoplasms
PubMed: 23821216
DOI: 10.1007/s12105-013-0464-x -
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 -
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 -
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 -
Advanced Biomedical Research 2012Myoepitheliomas are benign neoplasms of salivary glands derived from myoepithelial cells. These tumors can occur at any age but are most common in young adults. This...
Myoepitheliomas are benign neoplasms of salivary glands derived from myoepithelial cells. These tumors can occur at any age but are most common in young adults. This tumor is usually located in the parotid gland and the minor salivary glands of the soft palate and represents less than 1% of all salivary gland tumors. The myoepithelioma is classified in the follow cells types: spindle, plasmacytoid, reticular, epitheliod, and clear, additionally, mixed histological forms are described. The plasmacytoid myoepithelioma from palate salivary glands is considered as a rare entity. A 45-year-old lady presented with an asymptomatic, well-circumscribed, solid mass located on the hard palate, which was gradually increasing in size. A clinical impression of Pleomorphic Adenoma was made which on histopathological examination revealed cords, clusters, and sheets of homogenous, large cells with plasmacytoid characteristics and a prominent eosinophilic cytoplasm. Ductal and acinar differentiation were absent thus ruling out the pleomorphic adenoma, whereas, features consistent with plasmacytoid myoepithelioma were evident.
PubMed: 23326808
DOI: 10.4103/2277-9175.102985 -
Cases Journal Jan 2010Benign myoepithelioma is extremely rare in the lung, to the best of our knowledge; only five cases have been reported in the literature.
INTRODUCTION
Benign myoepithelioma is extremely rare in the lung, to the best of our knowledge; only five cases have been reported in the literature.
CASE REPORT
An 18-years woman complained from tiredness and fever during four months. Laboratory findings and fibroscopies were normal. CT of the thorax demonstrated a nodule in the left segment of the Fowler. Left inferior lobectomy was performed comporting a firm nodule of 25 mm, lifting the bronchial mucous membrane. Histologically, there was a proliferation of small cells of a plasmocytoid-type, with a predominantly whorled pattern. No mitotic activity or necrosis was seen in the tumor. Immuhistochemically, the tumor cells positive for smooth muscle actin, vimentine, and S100 protein. They were negatives for cytokeratine, chromogranine and HMB45. The diagnosis of benign myoepithelioma of the lung is so confirmed. The patient recovered well at 6 months follow-up.
CONCLUSION
Benign myoepithelioma is a rare pulmonary neoplasm distinct from pleomorphic adenoma, which should be considered in the differential diagnosis of lung nodules.
PubMed: 20180958
DOI: 10.1186/1757-1626-3-25