title: Colorectal cancer in inflammatory bowel diseases: CT features with pathological correlation.
abstract: OBJECTIVE
  To describe CT features of inflammatory bowel disease (IBD)-related colorectal cancer and correlate the imaging findings with histopathological findings.
  
  
  METHODS
  CT imaging findings in 17 patients with IBD-related colorectal cancer were retrospectively evaluated. Imaging findings were correlated with surgical and histopathological findings. Univariate and multivariate analyses explored the relationships between CT and histopathological variables.
  
  
  RESULTS
  Two different CT patterns were individualized including clearly visible soft tissue mass (8/17; 47%) (Type 1 tumor) or stenosis with marked circumferential thickening resembling inflammation (9/17; 53%) (Type 2 tumor). At univariate analysis, thickness of tumor-free colorectal wall at CT was greater in Crohn disease (median, 13 mm) than in ulcerative colitis (median, 7 mm) (P = 0.011). Significant association was found between presence of signet ring cells and Type 2 tumor at CT (6/9, 67% P = 0.009) and colonic dilatation proximal to tumor (5/6, 83%; P = 0.035). At multivariate analysis, free-fluid effusion was the single independent CT variable predictive for the presence of signet ring cells (odds ratio = 50; 95% CI 2.56-977.02; P = 0.01).
  
  
  CONCLUSIONS
  Colorectal cancer in IBD displays two main features on CT. Type 2 tumors and free-fluid effusion correlate with presence of signet ring cells. Knowledge of these findings is critical to help suggest the diagnosis.
authors.affiliation: Department of Abdominal Imaging, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, 2 Rue Ambroise Paré, Paris, France. lora.hristova@lrb.aphp.fr
authors.forename: Lora
authors.initials: L
authors.lastname: Hristova
authors.forename: Philippe
authors.initials: P
authors.lastname: Soyer
authors.forename: Christine
authors.initials: C
authors.lastname: Hoeffel
authors.forename: Philippe
authors.initials: P
authors.lastname: Marteau
authors.forename: Abderrahim
authors.initials: A
authors.lastname: Oussalah
authors.forename: Anne
authors.initials: A
authors.lastname: Lavergne-Slove
authors.forename: Mourad
authors.initials: M
authors.lastname: Boudiaf
authors.forename: Anthony
authors.initials: A
authors.lastname: Dohan
authors.forename: Valérie
authors.initials: V
authors.lastname: Laurent
mesh_terms: D000328:Adult; D000368:Aged; D003093:Colitis, Ulcerative / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology; D015179:Colorectal Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging* / Q000473:pathology; D003424:Crohn Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015212:Inflammatory Bowel Diseases / Q000150:complications* / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed