title: [Can preoperative fine-needle aspiration of parotid tumors pose problems for a definitive histological diagnosis?].
abstract: BACKGROUND
  Fine-needle aspiration cytology (FNAC) is a minimally invasive procedure that offers high specifity and acceptable sensitivity in the preoperative diagnosis of parotid tumors. FNAC provides information that can be particularly valuable in surgical planning and patient education. In some cases, it may even help prevent unnecessary surgery. After an FNA procedure, on rare occasions, morphological changes in the tumor may be observed and can make a definitive histological examination difficult or even impossible.
  
  
  METHODS
  Histopathological changes in parotid tumors after preoperative FNAC are described on the basis of a case report and a survey of the literature.
  
  
  RESULTS
  In rare cases, puncture-induced histopathological changes, such as hyalinization of the subepithelial stroma, necrosis and squamous metaplasia, so extensive that a definitive histological diagnosis is difficult, are observed. In the present case report, fine-needle aspiration of a 3 x 2 cm tumor, which had been classified as malignant on the basis of cytological findings, resulted in complete necrosis and made a definitive histological diagnosis impossible. Similar cases have been described by other authors in recent years.
  
  
  CONCLUSIONS
  In rare cases, histological changes in the tumor tissue can occur after an FNA procedure, making a definitive histological examination difficult or even impossible. When a preoperative FNAC is performed, the pathologist in charge should be advised accordingly. In addition, patients should be informed about this infrequent risk before undergoing the procedure.
authors.affiliation: Abteilung Hals-Nasen-Ohren-Heilkunde, Kopf- und Halschirurgie, Bundeswehrkrankenhaus Ulm, Ulm, Germany. mail@prof-heinz-maier.de
authors.forename: H
authors.initials: H
authors.lastname: Maier
authors.forename: S
authors.initials: S
authors.lastname: Frühwald
authors.forename: S
authors.initials: S
authors.lastname: Sommer
authors.forename: M
authors.initials: M
authors.lastname: Tisch
mesh_terms: D000368:Aged; D044963:Biopsy, Fine-Needle / Q000379:methods*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D010307:Parotid Neoplasms / Q000473:pathology* / Q000601:surgery*; D011300:Preoperative Care / Q000379:methods*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity