title: Spindle cell myoepithelial tumours of the parotid gland with extensive lipomatous metaplasia. A report of four cases with immunohistochemical and ultrastructural findings.
abstract: We report four cases of parotid gland tumours composed predominantly of spindle-shaped myoepithelial cells and mature adipocytes. The central portion of one tumour showed extensive adipose differentiation, whereas in the peripheral parts there were small foci of ductal epithelium arranged in cords and tubules within an abundant myxoid stroma. The other cases were adipose spindle cell myoepitheliomas without an obvious glandular component. Under high-power examination, a transition between modified spindle-shaped myoepithelial cells and adipocytes was observed, and this was confirmed with immunohistochemistry. Ultrastructurally, the modified myoepithelial cells showed intracytoplasmic tonofilaments, bundles of actin microfilaments and lipid droplets. A possible pathogenesis is proposed of true metaplastic transformation of myoepithelial cells to adipocytes. This lesion is important to identify correctly, as inadequate surgery can lead to recurrence.
authors.affiliation: Sikl's Department of Pathology, Medical Faculty Hospital, Plzen, Czech Republic. skalova@fnplzen.cz
authors.forename: A
authors.initials: A
authors.lastname: Skálová
authors.forename: I
authors.initials: I
authors.lastname: Stárek
authors.forename: R H
authors.initials: RH
authors.lastname: Simpson
authors.forename: V
authors.initials: V
authors.lastname: Kucerová
authors.forename: J
authors.initials: J
authors.lastname: Dvorácková
authors.forename: R
authors.initials: R
authors.lastname: Curík
authors.forename: M
authors.initials: M
authors.lastname: Dusková
mesh_terms: D008949:Adenoma, Pleomorphic / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D017667:Adipocytes / Q000737:chemistry / Q000473:pathology; D000273:Adipose Tissue / Q000737:chemistry / Q000473:pathology*; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D022083:Cytoplasmic Structures / Q000648:ultrastructure; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000032:analysis; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D009208:Myoepithelioma / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D010307:Parotid Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D007381:Intermediate Filament Proteins