title: Paradental cyst is an inclusion cyst of the junctional/sulcular epithelium of the gingiva: histopathologic and immunohistochemical confirmation for its pathogenesis.
abstract: OBJECTIVE
  The aim of this study was to characterize the histologic and immunohistochemical profiles of paradental cyst-lining epithelia to clarify its histopathogenesis.
  
  
  METHODS
  Ten surgical specimens of paradental cysts were examined for clinical profiles and to determine the histopathologic characteristics of the lining epithelia. Immunohistochemical profiles for keratin (K) subtypes, as well as for perlecan, UEA-I lectin binding, and proliferating cell nuclear antigen (PCNA), were determined and compared.
  
  
  RESULTS
  The paradental cyst was clinically characterized by its occurrence in young adults (mean age, 36.8 years; male, 42.8, female 27.8). Eight of the 10 cases arose in the retromolar area. The cyst wall was basically granulation tissue that was attached to the periodontal ligament space. Thin irregular anastomosing epithelial cords lined the cyst walls of immature granulation tissue with vascular dilation and hemorrhage. The intercellular space of the lining epithelia was widened with inflammatory cell infiltrates. Immunohistochemically, the lining was positive for K13, K14, K17, K19, UEA-I binding, and perlecan, suggesting its junctional/sulcular epithelial character.
  
  
  CONCLUSIONS
  The results showed that the paradental cyst was lined by epithelial cells with characteristics of the junctional/sulcular epithelium. The cyst can thus be considered as a kind of inclusion cyst arising in the periodontal pocket, most frequently of the mandibular third molars of young adults.
authors.affiliation: Lecturer, Oral Pathology Section, Department of Surgical Pathology, Niigata University Hospital, Niigata, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Maruyama
authors.affiliation: Assistant Professor, Division of Oral Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Yamazaki
authors.affiliation: Resident, Oral Pathology Section, Department of Surgical Pathology, Niigata University Hospital; Graduate Student, Division of Oral Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Abé
authors.affiliation: Graduate Student, Division of Oral Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Hamzah
authors.initials: H
authors.lastname: Babkair
authors.affiliation: Associate Professor, Division of Oral Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Professor, Division of Oral Pathology, Niigata University Graduate School of Medical and Dental Sciences and Oral Pathology Section, Department of Surgical Pathology, Niigata University Hospital, Niigata, Japan. Electronic address: tsaku@dent.niigata-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Saku
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010509:Periodontal Cyst / Q000473:pathology* / Q000601:surgery