title: Endoscopic ultrasonography-guided fine needle aspiration biopsy in follow-up patients with gastrointestinal stromal tumours.
abstract: OBJECTIVE
  Since all gastrointestinal stromal tumours (GISTs) are practically considered to be potentially malignant, they must be clinically differentiated from other submucosal tumours (SMTs). In this study, we carried out endoscopic ultrasonography-guided fine needle aspiration biopsy (EUS-FNAB) against follow-up SMTs to examine whether the method is sufficient for pathological diagnosis and analysis of c-kit mutation. The relationship between tumour growth and c-kit mutation was also examined.
  
  
  METHODS
  The tumour tissues were obtained by EUS-FNAB from 10 Japanese follow-up cases with SMT. Paraffin sections of tissues were used for haematoxylin and eosin staining, and for immunohistochemistry. Genomic DNA was extracted from the sections, and c-kit gene fragments of exons 9, 11, 13 and 17 were amplified by polymerase chain reaction and directly sequenced.
  
  
  RESULTS
  Nine SMTs were diagnosed as GIST and one was diagnosed as schwannoma by immunohistochemistry. Mutation at exon 11 was detected in six of nine GISTs, but no mutations were detected at exons 9, 13 and 17 in all GISTs. The case of schwannoma did not have any mutations at exons 9, 11, 13 and 17. Statistical significance was not observed between the average growth rate of six GISTs with the mutation and that of three GISTs without the mutation (P = 0.694).
  
  
  CONCLUSIONS
  EUS-FNAB against SMTs was useful for the differential diagnosis of SMT and the analysis of c-kit mutation. The c-kit mutation might not be one of the predictable markers for rapid tumour growth.
authors.affiliation: Department of Internal Medicine and Molecular Science, Graduate School of Medicine, Osaka University Medical School, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kinoshita
authors.forename: Koji
authors.initials: K
authors.lastname: Isozaki
authors.forename: Shusaku
authors.initials: S
authors.lastname: Tsutsui
authors.forename: Shinji
authors.initials: S
authors.lastname: Kitamura
authors.forename: Shintaro
authors.initials: S
authors.lastname: Hiraoka
authors.forename: Kenji
authors.initials: K
authors.lastname: Watabe
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakahara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nagasawa
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kiyohara
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Seiichi
authors.initials: S
authors.lastname: Hirota
authors.forename: Toshirou
authors.initials: T
authors.lastname: Nishida
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Shinomura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsuzawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle / Q000379:methods*; D019160:Endosonography; D005091:Exons; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D005773:Gastroscopy; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D013194:Staining and Labeling; D018084:Ultrasonography, Interventional / Q000379:methods
chemical_list: D019009:Proto-Oncogene Proteins c-kit