title: Synchronous incidental gastrointestinal stromal and epithelial malignant tumors.
abstract: OBJECTIVE
  To investigate the incidence of incidental gastrointestinal stromal tumor (GIST) and its etiopathogenesis.
  
  
  METHODS
  From January 1, 2000 to December 31, 2007, 13804 cases of gastrointestinal epithelial malignant tumor (EMT) and 521 cases of pancreatic adenocarcinoma (PAC) were successfully treated with surgery at the Department of General Surgery and the Department of Thoracic Surgery, West China Hospital, Sichuan University, China. The clinical and pathologic data of 311 cases of primary GIST, including 257 cases with clinical GIST and 54 cases of incidental GIST were analyzed.
  
  
  RESULTS
  Of the 311 patients, 54 had incidental GIST, accounting for 17.4%. Of these tumors, 27 were found in 1.13% patients with esophageal squamous cell carcinoma (ESCC), 22 in 0.53% patients with gastric adenocarcinoma (GAC), 2 in 0.38% patients with PAC, 2 in 0.03% patients with colorectal adenocarcinoma, and 1 in one patient with GAC accompanying ESCC, respectively. Patients with incidental GIST presented symptoms indistinguishable from those with EMT. All incidental GIST lesions were small in size, and the majority had a low mitotic activity while only 1.9% (5/257) of clinical GIST lesions had a high risk.
  
  
  CONCLUSIONS
  Incidental GIST may occur synchronously with other tumors and has a high prevalence in males. Surgery is its best treatment modality.
authors.affiliation: Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Liu
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yang
authors.forename: Lang-Song
authors.initials: LS
authors.lastname: Hao
authors.forename: Lin
authors.initials: L
authors.lastname: Xia
authors.forename: Qian-Bin
authors.initials: QB
authors.lastname: Jia
authors.forename: Xiao-Ting
authors.initials: XT
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D015897:Comorbidity; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies