title: CT Features of Colorectal Schwannomas: Differentiation from Gastrointestinal Stromal Tumors.
abstract: OBJECTIVE
  To find differential CT features of colorectal schwannomas from gastrointestinal stromal tumors (GISTs).
  
  
  METHODS
  CT features of 13 pathologically proven colorectal schwannomas and 21 GISTs were retrospectively reviewed. The following CT items were analyzed: size, longitudinal and transverse location, shape, margin, homogeneity, necrosis, surface ulceration, calcification, degree of attenuation, the presence of enlarged lymph node (LN), and metastasis. Among the features, significant variables were evaluated using univariate statistical tests. The optimal cut-off point of tumor size was obtained by ROC analysis. Binary logistic regression analysis was used to find the most independent CT variables.
  
  
  RESULTS
  Small size, non-rectum location, smooth margin, homogeneous high attenuation without necrosis, and the presence of enlarged LNs were found to be significant variables to differentiate schwannomas from GISTs (P<0.05). The optimized cut-off point for tumor size in distinguishing GISTs from schwannomas was 3.9 cm (AUC = 0.808, sensitivity = 66.7%, specificity = 92.3%, P<0.0001). Binary regression analysis revealed that only non-rectum location remained independent predictor for schwannomas differentiated from GISTs (odds ratio = 31.667, P = 0.001).
  
  
  CONCLUSIONS
  Colorectal schwannomas usually located in non-rectum and appear as small subepithelial nodules showing homogeneous high attenuation and smooth margin. Schwannomas exclusively accompany with enlarged LNs.
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ji Hee
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Korea.|Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Radiology, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung Eun
authors.initials: SE
authors.lastname: Rha
authors.affiliation: Department of Radiology, National Cancer Center, Goyang, Korea.
authors.forename: Bo Yun
authors.initials: BY
authors.lastname: Hur
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Korea.|Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000175:diagnosis* / Q000473:pathology; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed