title: A single ThinPrep slide may not be representative in all head and neck fine needle aspirate specimens.
abstract: OBJECTIVE
  Ideally, head and neck aspiration should be performed by trained aspirators within the setting of a one-stop clinic, where smeared material is available for immediate assessment. However, this may not always be possible for practical reasons and the use of liquid-based techniques in head and neck cytology is increasing. Although liquid-based cytology has been extensively validated for use in gynaecological cytology, no studies have investigated whether or not a single ThinPrep slide is representative for head and neck aspirate specimens. We performed a prospective audit of head and neck fine needle aspiration specimens processed by the ThinPrep method to investigate whether a single ThinPrep slide was representative.
  
  
  METHODS
  A prospective audit of 115 consecutive head and neck aspirates was carried out. A single ThinPrep slide was prepared and a diagnosis recorded. The remainder of the specimen was then spun down and prepared as a cell block. The ThinPrep and cell block diagnoses were compared.
  
  
  RESULTS
  In 36 cases (31%), the cell block provided additional information that contributed to the diagnosis. In 14 (12%), the cell block was regarded as essential to the diagnosis.
  
  
  CONCLUSIONS
  A single ThinPrep slide may not provide representative diagnostic material in all head and neck aspirates. This should be taken into consideration when contemplating the use of liquid-based methods for non-gynaecological cytology.
authors.affiliation: Department of Pathology, Laboratories Directorate, Royal Infirmary of Edinburgh, Edinburgh, UK.
authors.forename: C E
authors.initials: CE
authors.lastname: Anderson
authors.forename: E
authors.initials: E
authors.lastname: Duvall
authors.forename: W A
authors.initials: WA
authors.lastname: Wallace