title: A diagnosis of malignant pleural mesothelioma can be made by effusion cytology:  results of a 20 year audit.
abstract: Cytological diagnosis of malignant pleural mesothelioma (MPM) is controversial, but has been used in our institution for over 30 years. To assess the role of effusion cytology in mesothelioma diagnosis we conducted an audit of pleural fluid cytology results over a 20 year period (1988-2007).
  
  
  
  Pleural samples were received from 6285 patients; data linkage with Western Australian Cancer and Mesothelioma Registries demonstrated that 815 of these patients had a diagnosis of MPM. Cytological examination of a pleural effusion specimen had been performed in 517 (63%) of these 815 patients.
  
  
  
  Definitive cytological diagnosis of MPM was made in 377/517 cases, resulting in an 'absolute' sensitivity of 73%. An additional 66 patients were diagnosed as atypical/suspicious, resulting in a 'complete' sensitivity of 86%. If only biopsy/necropsy proven cases are considered, the absolute sensitivity is 68% and the complete sensitivity is 82%. There were no false positive diagnoses of malignancy; two patients with metastatic adenocarcinoma were initially diagnosed as MPM, prior to the availability of specific mesothelial markers, resulting in a positive predictive value of 99%.
  
  
  
  Effusion cytology is an inexpensive, minimally invasive procedure which should be included in the diagnostic work-up of cases of suspected MPM.
authors.affiliation: PathWest Laboratory Medicine WA, Queen Elizabeth II Medical Centre, Perth, Australia. Amanda.segal@health.wa.gov.au
authors.forename: Amanda
authors.initials: A
authors.lastname: Segal
authors.forename: Gregory F
authors.initials: GF
authors.lastname: Sterrett
authors.forename: Felicity A
authors.initials: FA
authors.lastname: Frost
authors.forename: Keith B
authors.initials: KB
authors.lastname: Shilkin
authors.forename: Nola J
authors.initials: NJ
authors.lastname: Olsen
authors.forename: Arthur William
authors.initials: AW
authors.lastname: Musk
authors.forename: Anna K
authors.initials: AK
authors.lastname: Nowak
authors.forename: Bruce William S
authors.initials: BW
authors.lastname: Robinson
authors.forename: Jenette
authors.initials: J
authors.lastname: Creaney
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054869:Clinical Audit; D003581:Cytodiagnosis; D005122:Exudates and Transudates; D005260:Female; D006801:Humans; D008297:Male; D008654:Mesothelioma / Q000175:diagnosis*; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000175:diagnosis*; D010997:Pleural Neoplasms / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013997:Time Factors; D014904:Western Australia; D055815:Young Adult