title: Simultaneous occurrence of synchronous and metachronous tumors with gastrointestinal stromal tumors.
abstract: OBJECTIVE
  To examine the frequency and clinicopathological features of synchronous and metachronous tumors which occur simultaneously with gastrointestinal stromal tumors (GIST).
  
  
  METHODS
  Clinical and pathologic records of 78 patients diagnosed with primary GIST and treated at our institution between 1997 and 2009 were reviewed.
  
  
  RESULTS
  GIST occurred simultaneously with other primary GI malignancies in 16.1 % (n = 13) of all patients with GIST. Of the simultaneous secondary tumors, 69.2 % (n = 9) were gastrointestinal tumors, and the remaining were biliary system and breast tumors. GIST most frequently had gastric localization (n = 6, 46.1%).
  
  
  CONCLUSIONS
  Although GIST are uncommon neoplasms, their synchronous and metachronous coexistence with other tumors is rather frequent, mostly as incidental tumors accompanying a gastrointestinal neoplasm. Therefore, during surgery on cases with gastrointestinal neoplasms, the surgeon needs to be careful about a synchronous GIST. At the same time, more detailed studies are needed about the carcinogenesis of dual tumors coexisting with GIST (Tab. 1, Ref. 14).
authors.affiliation: Department of Surgical Pathology, Uludag University, Faculty of Medicine, Bursa, Turkiye. sadumanbalaban@hotmail.com
authors.forename: S B
authors.initials: SB
authors.lastname: Adim
authors.forename: G
authors.initials: G
authors.lastname: Filiz
authors.forename: O
authors.initials: O
authors.lastname: Kanat
authors.forename: O
authors.initials: O
authors.lastname: Yerci
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000473:pathology*; D046152:Gastrointestinal Stromal Tumors / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000473:pathology*