title: [Study on clinicopathologic parameters of malignant behavior in gastrointestinal stromal tumors].
abstract: OBJECTIVE
  To determinate the clinicopathologic parameters in predicting the malignant behavior of gastrointestinal stromal tumor (GIST).
  
  
  METHODS
  Eight hundred and forty cases of GIST were retrospectively reviewed. The tumors were classified as malignant if they met any of the following criteria: evidence of gross dissemination (including liver metastasis and/or peritoneal spread), evidence of microscopic dissemination (including lymph node metastasis, infiltration to vessels, fat tissue, nerves and/or mucosal tissue), or disease relapse. The remaining cases were provisionally classified as tumors of uncertain biologic behavior. A number of morphologic parameters were then evaluated under light microscopy and univariate and multivariate analyses were adopted for this study.
  
  
  RESULTS
  Histologic findings correlated with evidences of the following morphologic parameters were considered in accord with the criteria of the malignant behavior: mitotic count>or=10 per 50 high-power fields (P<0.01), muscle infiltration (P<0.01), coagulative necrosis (P<0.01), perivascular growth pattern (P=0.005) and remarkable nuclear atypia (P=0.014). Basing on the above criterion, 485 cases were re-classified as "malignant" and 355 cases "non-malignant". Follow-up data showed that the five-year disease-free survival and overall survival in the "non-malignant" group were 99.3% and 100% respectively, in contrast to 43.9% and 59.7% respectively in the "malignant" group (P<0.01).
  
  
  CONCLUSIONS
  The set of clinicopathologic parameters is useful in predicting the malignant behavior of GIST and prognosis.
authors.affiliation: Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai 200032, China. houyingyong@hotmail.com
authors.forename: Ying-yong
authors.initials: YY
authors.lastname: Hou
authors.forename: Xiong-zeng
authors.initials: XZ
authors.lastname: Zhu
authors.forename: Shao-hua
authors.initials: SH
authors.lastname: Lu
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhou
authors.forename: Jun
authors.initials: J
authors.lastname: Hou
authors.forename: Yun-shan
authors.initials: YS
authors.lastname: Tan
authors.forename: Kun-tang
authors.initials: KT
authors.lastname: Shen
authors.forename: Jing
authors.initials: J
authors.lastname: Qin
authors.forename: Yi-hong
authors.initials: YH
authors.lastname: Sun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D046152:Gastrointestinal Stromal Tumors / Q000145:classification* / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D010529:Peritoneal Cavity / Q000473:pathology*; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D055815:Young Adult