title: Natural history of low grade dysplasia in patients with primary sclerosing cholangitis and ulcerative colitis.
abstract: OBJECTIVE
  Patients with ulcerative colitis (UC) and primary sclerosing cholangitis (PSC) are at increased risk of colon cancer. The aim of this study was to determine the natural history of LGD and its progression to high grade dysplasia (HGD)/colorectal cancer (CRC) in PSC-UC patients.
  
  
  METHODS
  Ten PSC-UC patients with LGD who underwent surveillance colonoscopy from 1996 to 2011 were evaluated. Raised dysplasia was defined as a discrete raised lesion located in an area involved by either quiescent or active colitis that was endoscopically resected, while flat dysplasia was defined as the absence of documentation of a raised lesion.
  
  
  RESULTS
  Of the 10 patients with LGD, 3 (30%) progressed to raised HGD over a mean follow-up of 13±11 months. Three of 10 patients had initial raised LGD while 7 had flat LGD. The location of HGD was in the proximal colon in all 3 patients. However all 3 patients who progressed to HGD had initial dysplasia located in the distal colon and had flat morphology. The incidence rate for detection of HGD/CRC was 9.4 cases per 100 person years at risk. Patients with LGD with flat morphology had an incidence rate of 17.8 cases per 100 person years at risk. HGD occurred more frequently within the first year of initial detection of LGD (23.5 per 100 patient years of follow-up).
  
  
  CONCLUSIONS
  One-third of patients with LGD progressed to HGD/CRC in PSC-UC. Most patients progress within the first year of diagnosis of LGD supporting early colectomy in PSC-UC patients with LGD.
authors: Department of Gastroenterology, Digestive Disease Institute, The Cleveland Clinic, Cleveland, OH, USA.
authors: Preethi G K
authors: PG
authors: Venkatesh
authors: Ramprasad
authors: R
authors: Jegadeesan
authors: Norma G
authors: NG
authors: Gutierrez
authors: Madhusudhan R
authors: MR
authors: Sanaka
authors: Udayakumar
authors: U
authors: Navaneethan
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D015209:Cholangitis, Sclerosing / Q000150:complications / Q000473:pathology*; D003082:Colectomy; D003093:Colitis, Ulcerative / Q000150:complications / Q000473:pathology*; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology*; D003113:Colonoscopy; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors
keywords: 5-ASA; 5-aminosalicylic acid; ACG; American College of Gastroenterology; CD; Crohn's disease; DALM; Flat dysplasia;; HGD; IBD; IC; LGD; Low grade dysplasia;; PSC; Primary sclerosing cholangitis; UC; Ulcerative colitis;; dysplasia associated lesion or mass; high grade dysplasia; indeterminate colitis; inflammatory bowel disease; low grade dysplasia; primary sclerosing cholangitis; ulcerative colitis