title: Histopathological features that predict the recurrence of odontogenic keratocysts.
abstract: BACKGROUND
  Odontogenic keratocysts (OKCs) constitute between 1.8% and 21.5% of odontogenic cysts and are associated with higher propensity to recur than other odontogenic cysts following surgical removal. Previous studies have been performed to identify clinico-pathological predictive factors in relation to such behaviour. The relationship between the presence of hyalinisation and recurrence of the OKC has not been explored.
  
  
  METHODS
  A total of 110 OKCs were selected, comprising 53 non-recurrent cases, 50 cases known to subsequently recur and seven syndromic cases. Cases were examined blind, and histological assessment of the epithelial lining, connective tissue capsule and cyst lumen was made. Statistical analysis was completed using Pearson Chi-square, Fisher's exact test and logistic regression analysis.
  
  
  RESULTS
  Subepithelial hyalinisation of the underlying connective tissue capsule (P = 0.006) was significantly more common in OKC that recurred. Recurring cysts demonstrating hyalinisation were seen in a younger age group (mean = 40.8 years) than the non-recurrent cysts (mean = 56.4 years). In addition, subepithelial splitting (P = 0.015) and the position of mitotic figures (P = 0.033) were more common in recurring cysts.
  
  
  CONCLUSIONS
  In this case series, several differences were found in relation to histological features of recurring and non-recurring OKCs. There are many factors responsible for the high recurrence rate of OKCs, and the presence of subepithelial hyalinisation may be used as an additional histopathological feature to predict a greater tendency for recurrence.
authors.affiliation: Unit of Oral and Maxillofacial Pathology, School of Clinical Dentistry, University of Sheffield, Sheffield, UK.
authors.forename: Hannah E
authors.initials: HE
authors.lastname: Cottom
authors.forename: Faten I
authors.initials: FI
authors.lastname: Bshena
authors.forename: Paul M
authors.initials: PM
authors.lastname: Speight
authors.forename: Geoffrey T
authors.initials: GT
authors.lastname: Craig
authors.forename: Adam V
authors.initials: AV
authors.lastname: Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001478:Basal Cell Nevus Syndrome / Q000150:complications* / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D006818:Hyalin / Q000378:metabolism*; D007573:Jaw Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009807:Odontogenic Cysts / Q000150:complications / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D009808:Odontogenic Tumors / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D012008:Recurrence; D016037:Single-Blind Method; D055815:Young Adult