Document Detail


Myoepithelial tumors of salivary glands: a clinicopathologic, immunohistochemical, ultrastructural, and flow-cytometric study.
MedLine Citation:
PMID:  8734420     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Myoepitheliomas of the salivary glands remain a controversial entity. To contribute to the knowledge of this entity, 16 myoepithelial tumors of the salivary glands were studied: 12 benign myoepitheliomas (BME) and 4 malignant myoepitheliomas (MME). The clinical and the histologic findings of each case were studied Immunohistochemistry and flow-cytometry analysis were performed from the paraffin-embedded material in 15 cases. An electron-microscopy study was performed in 8 cases. The myoepithelial tumors affected patients of both sexes equally. The mean age of the patients with BME was 54 years, and the mean age of patients with MME was 62 years. Eight cases of BME originated in the parotid gland and 4 cases originated in the minor salivary glands. All the MME developed from a benign preexistent tumor: two developed from a pleomorphic adenoma in the parotid gland, and the other two MME developed in the minor salivary gland from a BME. The myoepithelial tumors were composed of epithelioid, plasmacytoid, spindle, or clear cell types, and they showed a solid or a myxoid pattern of growth. Immunohistochemical studies revealed marked and diffuse positivity to cytokeratins, vimentin, and S-100 protein in all cases. Glial fibrillary acidic protein was positive in 8 cases (53%), and muscle-specific actin and smooth-muscle actin were positive in only 3 cases (20%); they were all cases of BME. Desmin was negative in all tumors. Ultrastructural studies showed the presence of basal membrane, tight junctions, intermediate filaments, and microvilli as well as actin-like filaments lacking focal densities in all cases. But actin-like filaments with focal densities were not identified. Flow cytometry determined that all BME were diploid with a mean proliferative index of 7.73%. Two of the MME were diploid and the other two MME were aneuploid. The mean proliferative index of MME was 11.93%. In conclusion, BME and MME originated in major and minor salivary glands can display different histologic patterns and cellular features. Some immunohistochemical and ultrastructural characteristics have been found in all these neoplasms, which supports the idea that myoepitheliomas are composed by neoplastic modified myoepithelial cells, not fully differentiated. These techniques can be useful for the diagnosis of these tumors.
Authors:
L Alós; A Cardesa; J A Bombí; C Mallofré; A Cuchi; J Traserra
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Seminars in diagnostic pathology     Volume:  13     ISSN:  0740-2570     ISO Abbreviation:  Semin Diagn Pathol     Publication Date:  1996 May 
Date Detail:
Created Date:  1996-10-17     Completed Date:  1996-10-17     Revised Date:  2007-05-16    
Medline Journal Info:
Nlm Unique ID:  8502262     Medline TA:  Semin Diagn Pathol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  138-47     Citation Subset:  IM    
Affiliation:
Department of Pathology, Hospital Clínic i Provincial, University of Barcelona Medical School, Spain.
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MeSH Terms
Descriptor/Qualifier:
Adult
Aged
Aged, 80 and over
Carcinoma / chemistry,  pathology*,  ultrastructure
DNA, Neoplasm / analysis,  genetics
Desmin / analysis
Female
Flow Cytometry
Glial Fibrillary Acidic Protein / analysis
Humans
Immunohistochemistry
Keratins / analysis
Male
Maxillary Neoplasms / chemistry,  pathology,  ultrastructure
Microscopy, Electron
Middle Aged
Myoepithelioma / chemistry,  pathology*,  ultrastructure
Parotid Neoplasms / chemistry,  pathology,  ultrastructure
Ploidies
S100 Proteins / analysis
Salivary Gland Neoplasms / chemistry,  pathology*,  ultrastructure
Salivary Glands / chemistry,  pathology,  ultrastructure
Salivary Glands, Minor / chemistry,  pathology,  ultrastructure
Vimentin / analysis
Chemical
Reg. No./Substance:
0/DNA, Neoplasm; 0/Desmin; 0/Glial Fibrillary Acidic Protein; 0/S100 Proteins; 0/Vimentin; 68238-35-7/Keratins

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