title: [An electron microscopic histochemical study on the fibrous formation in pleomorphic adenoma of the salivary gland].
abstract: OBJECTIVE
  To study the kinds of fibers and mechanism of fibrous formation in myxochondroid tissue of pleomorphic adenoma.
  
  
  METHODS
  Eight cases of pleomorphic adenomas of salivary gland were studied by histological and electron microscopic histochemical techniques.
  
  
  RESULTS
  The histological study showed that collagenous fibers and elastic fibers which constituted the trestle were distributed in myxochondroid areas of pleomorphic adenoma. The electron microscopic histochemical study showed that the myxochondroid tissue contained slender collagen fibrils measuring 50 nm in diameter and heavily stained elastic fibers. In cytoplasm of the myxochondroid cells two types of the Golgi-derived vesicles were seen: one was small round vesicles with a uniform electron dense core of amorphous material and heavily stained; another type was small round vesicles with a non-uniform electron dense core of filamentous material and stained grey. These materials were released into the extracellular space by cytoplasmic exocytosis.
  
  
  CONCLUSIONS
  Neoplastic myoepithelial cells have the ability to synthesize and secrete procollagen and precursor of elastin, thus forming collagenous fibers and elastic fibers in myxochondroid areas.
authors.affiliation: Department of Pathology, School of Stomatology, Hebei Medical University, Shijiazhuang 050017, China.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: Q
authors.initials: Q
authors.lastname: Tang
mesh_terms: D008949:Adenoma, Pleomorphic / Q000648:ultrastructure*; D006651:Histocytochemistry; D006801:Humans; D008854:Microscopy, Electron; D012468:Salivary Gland Neoplasms / Q000648:ultrastructure*