title: Parotid gland tumors: histologic reevaluation and reclassification of 478 cases.
abstract: BACKGROUND
  The histologic classification of epithelial salivary gland tumors may present difficulties due to their great morphologic diversity.
  
  
  METHODS
  In this study, 478 parotid gland tumors were reevaluated and reclassified according to the 1991 WHO histologic classification of salivary gland tumors.
  
  
  RESULTS
  In 56 cases, the original diagnosis was changed, either within the benign or the malignant tumor group. In six cases (1.3%), the original diagnosis was changed from benign to malignant or vice versa.
  
  
  CONCLUSIONS
  During the mean follow-up period of 10.3 years, no events occurred supporting or rejecting the proposed change in diagnosis in these six patients. With regard to the three cases in which an original malignant diagnosis was made, the possibility of an overdiagnosis, and therefore an overtreatment, remains.
authors.affiliation: Department of Oral & Maxillofacial Surgery/Pathology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: J E
authors.initials: JE
authors.lastname: van der Wal
authors.forename: H
authors.initials: H
authors.lastname: Leverstein
authors.forename: G B
authors.initials: GB
authors.lastname: Snow
authors.forename: H A
authors.initials: HA
authors.lastname: Kraaijenhagen
authors.forename: I
authors.initials: I
authors.lastname: van der Waal
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D010306:Parotid Gland / Q000601:surgery; D010307:Parotid Neoplasms / Q000145:classification / Q000473:pathology* / Q000601:surgery