title: Ileocaecal junction carcinoma: a clinicopathological study of 199 cases.
abstract: OBJECTIVE
  The ileocaecal junction (ICJ) region is an epithelial transition zone in which carcinomas are frequently diagnosed. However, it is currently unknown whether ICJ carcinomas (ICJ-CAs) have distinctive features. This study aimed to characterize the clinicopathological features of ICJ-CAs.
  
  
  METHODS
  All ileal and colorectal resections for carcinoma, performed in Calgary, Canada between January 2009 and June 2012, were reviewed. Carcinomas in which the epicentre was within 5 cm of the ileocaecal valve (ICV) were defined as ICJ-CAs. Of 1003 carcinomas studied, 199 (19.8%) were ICJ-CAs, including 93 (9.3%) that crossed the ICV. Comparison of clinicopathological features with carcinomas of the other ileo-colorectal regions was made. Survival was also assessed.
  
  
  RESULTS
  Clinically, ICJ-CAs were more common in female than male patients (56.3% female) compared with left-colonic (42.9% female) and rectal (37.9% female) carcinomas, and were more common in older age-groups of patients (71.8 ± 12.7 years) compared with appendiceal (62.6 ± 11.3 years), left-colonic (69.4 ± 12.3 years) and rectal (67.1 ± 11.9 years) carcinomas. Macroscopically, ICJ-CAs were similar to other colorectal carcinomas and were mostly described as ulcerated (63.3%). Histologically, ICJ-CAs had more mucinous, signet-ring cell and/or neuroendocrine features (39.7%, 8.0% and 7.5%, respectively) than did carcinomas of the left colon (16.8%, 1.6% and 1.1%, respectively) and the rectum (14.1%, 1.0% and 0.0%, respectively). They were higher grade (20.1% were high grade) than those of the left-colon (10.3%) and the rectum (9.8%). ICJ-CAs presented at a higher T-stage (25.6% were T4) compared with rectal carcinomas (11.6%). Most significantly, ICJ-CAs presented at a higher N-stage (25.6% were N2) than did right-colonic (14.1%) and rectal (16.2%) carcinomas. Although survival of patients with ICJ-CAs did not differ from those with right-colonic carcinomas, those with carcinomas directly involving the ICV did show a significantly decreased survival.
  
  
  CONCLUSIONS
  ICJ-CAs display several distinct clinicopathological features that may require special diagnostic, prognostic and management attention.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: L H
authors.initials: LH
authors.lastname: Lee
authors.forename: A R
authors.initials: AR
authors.lastname: MacLean
authors.forename: V G
authors.initials: VG
authors.lastname: Falck
authors.forename: X
authors.initials: X
authors.lastname: Gui
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta; D002277:Carcinoma / Q000473:pathology*; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology; D002430:Cecal Neoplasms / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000473:pathology; D005260:Female; D006801:Humans; D007078:Ileal Neoplasms / Q000473:pathology*; D007080:Ileocecal Valve / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D012004:Rectal Neoplasms / Q000473:pathology; D012189:Retrospective Studies
keywords: Ileocaecal valve; caecal neoplasms; colorectal neoplasms; ileal neoplasms