title: Ultrastructure and three-dimensional imaging of epimyoepithelial islands in benign lymphoepithelial lesions.
abstract: Benign lymphoepithelial lesions of the salivary glands associated with Sjögren's syndrome are characterized by extensive infiltration of lymphoid cells, atrophy of acini and the presence of so-called epimyoepithelial islands. This report describes ultrastructural and three-dimensional reconstructive studies of epimyoepithelial islands performed at Tokyo Women's Medical College. Ultrastructural examination showed that these islands are composed mainly of epithelial cells containing intermediate filaments and/or tonofilament bundles, scattered lymphocytes and plasma cells. Myoepithelium-like cells containing myofilaments were sometimes found in the peripheral portion of the myoepithelial islands. Also, mitotic figures were rarely found in these islands. Three-dimensional reconstructive study revealed that the epimyoepithelial islands are not isolated cell clusters but are continuous hypertrophic duct-like structures. These results suggest that the epimyoepithelial islands are derived from proliferating duct epithelial cells, especially those of large peripheral ducts.
authors.affiliation: Department of Otolaryngology, Tokyo Women's Medical College, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yoshihara
authors.forename: M
authors.initials: M
authors.lastname: Morita
authors.forename: T
authors.initials: T
authors.lastname: Ishii
mesh_terms: D008841:Actin Cytoskeleton / Q000473:pathology / Q000648:ultrastructure; D000328:Adult; D002455:Cell Division; D048429:Cell Size; D003116:Color; D003196:Computer Graphics; D004848:Epithelium / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D006801:Humans; D006984:Hypertrophy; D007090:Image Interpretation, Computer-Assisted; D007382:Intermediate Filaments / Q000473:pathology / Q000648:ultrastructure; D008214:Lymphocytes / Q000473:pathology / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D010306:Parotid Gland / Q000473:pathology / Q000648:ultrastructure*; D010950:Plasma Cells / Q000473:pathology / Q000648:ultrastructure; D012859:Sjogren's Syndrome / Q000473:pathology*