title: [Study on the origin and differentiation of gastrointestinal stromal tumors].
abstract: OBJECTIVE
  To explore the origin and differentiation of gastrointestinal stromal tumors (GISTs).
  
  
  METHODS
  Immunohistochemistry staining and electron microscopy were adopted.
  
  
  RESULTS
  In 212 cases of primary GISTs, the positive rates of CD117, CD34, alpha-SMA, MSA, desmin, S-100, PGP9.5 were 96.7%, 77.3%, 19.3%, 15.6%, 1.9%, 16.3%, and 12.3% respectively. Among them, GISTs showed a diffuse and strong positivity for CD117. Electron microscopy of tumor cells demonstrated numerous mitochondria, prominent perinuclear Golgi complex, smooth and rough endoplasmical reticulum and intermediate filaments. Irregular caveolae, dense plaque, incontinuous basal lamina were observed occasionally. Cytoplasmic processes were often observed accompanying with local adhesion present between the processes or between the processes and the cell membrane.
  
  
  CONCLUSIONS
  Data from both immunophenotype and electron microscopy suggest that GIST might originate from the mesenchymal cells, differentiating to be ICC afterwards, and possessing myoid characteristics in various extent.
authors.affiliation: Department of Pathology, Cancer Hospital, Medical College of Fudan University, Shanghai 200032, China.
authors.forename: Ying-yong
authors.initials: YY
authors.lastname: Hou
authors.forename: Xiong-zeng
authors.initials: XZ
authors.lastname: Zhu
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Yun-shan
authors.initials: YS
authors.lastname: Tan
authors.forename: Meng-hong
authors.initials: MH
authors.lastname: Sun
authors.forename: Xiang
authors.initials: X
authors.lastname: Du
authors.forename: Da-ren
authors.initials: DR
authors.lastname: Shi
mesh_terms: D002454:Cell Differentiation; D046152:Gastrointestinal Stromal Tumors / Q000737:chemistry / Q000648:ultrastructure*; D006056:Golgi Apparatus / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D009418:S100 Proteins / Q000032:analysis*; D017154:Stromal Cells / Q000737:chemistry / Q000648:ultrastructure; D043222:Ubiquitin Thiolesterase / Q000032:analysis
chemical_list: D009418:S100 Proteins; C482860:UCHL1 protein, human; D019009:Proto-Oncogene Proteins c-kit; D043222:Ubiquitin Thiolesterase