View source for Myoepithelial cell

'''Myoepithelial cells''' (sometimes referred to as '''Myoepithelium''') are [[Cell (biology)|cells]] usually found in [[glandular epithelium]] as a thin layer above the [[basement membrane]] but generally beneath the [[lumen (anatomy)|lumenal]] cells. These may be positive for [[ACTA2|alpha smooth muscle]] [[actin]] and can contract and expel the [[secretions]] of [[exocrine glands]]. They are found in the [[sweat gland]], [[mammary gland]], [[lacrimal gland]], and [[salivary gland]]. Myoepithelial cells in these cases constitute the [[basal cell layer]] of an [[epithelium]] that harbors the epithelial [[Progenitor cell|progenitor]]/[[stem cells]]. In the case of [[wound healing]], myoepithelial cells reactively [[proliferate]]. Presence of myoepithelial cells in a [[hyperplasia|hyperplastic]] tissue proves the [[benign]]ity of the gland and, when absent, indicates [[cancer]]. Only rare cancers like [[adenoid cystic carcinoma]]s contains [[myofibroblast]]s as one of the [[malignant]] components.

==Markers==
Myoepithelial cells are true [[epithelial cell]]s positive for [[keratin]]s, not to be confused with myofibroblasts which are true [[mesenchymal cell]]s positive for [[vimentin]].  These cells are generally positive for [[alpha smooth muscle]] actin (αSMA),  [[cytokeratin]] 5/6 and other high [[molecular weight]] cytokeratins, [[TP73L|p63]] and [[caldesmon]].

==External links==
* {{eMedicineDictionary|Myoepithelium}}
 
* {{AnatomyAtlasesMicroscopic|07|141}} - "Axillary Sweat Gland: Myoepithelium"
* {{OklahomaHistology|43_13}} - "thick skin"
* {{KansasHistology|glands|glands09}} "Simple Tubular Coiled"
* {{GeorgiaPhysiology|6/6ch4/s6ch4_4}}

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[[de:Myoepithelzelle]]
[[ja:筋上皮細胞]]
[[pl:Komórka mioepitelialna]]