title: The Role of Liquid Based Cytology and Ancillary Techniques in the Peritoneal Washing Analysis: Our Institutional Experience.
abstract: BACKGROUND
  The cytological analysis of peritoneal effusions serves as a diagnostic and prognostic aid for either primary or metastatic diseases. Among the different cytological preparations, liquid based cytology (LBC) represents a feasible and reliable method ensuring also the application of ancillary techniques (i.e immunocytochemistry-ICC and molecular testing).
  
  
  METHODS
  We recorded 10348 LBC peritoneal effusions between January 2000 and December 2014. They were classified as non-diagnostic (ND), negative for malignancy-NM, atypical-suspicious for malignancy-SM and positive for malignancy-PM.
  
  
  RESULTS
  The cytological diagnosis included 218 ND, 9.035 NM, 213 SM and 882 PM. A total of 8048 (7228 NM, 115SM, 705 PM) cases with histological follow-up were included. Our NM included 21 malignant and 7207 benign histological diagnoses. Our 820 SMs+PMs were diagnosed as 107 unknown malignancies (30SM and 77PM), 691 metastatic lesions (81SM and 610PM), 9 lymphomas (2SM and 7PM), 9 mesotheliomas (1SM and 8SM), 4 sarcomas (1SM and 3PM). Primary gynecological cancers contributed with 64% of the cases. We documented 97.4% sensitivity, 99.9% specificity, 98% diagnostic accuracy, 99.7% negative predictive value (NPV) and 99.7% positive predictive value (PPV). Furthermore, the morphological diagnoses were supported by either 173 conclusive ICC results or 50 molecular analyses. Specifically the molecular testing was performed for the EGFR and KRAS mutational analysis based on the previous or contemporary diagnoses of Non Small Cell Lung Cancer (NSCLC) and colon carcinomas. We identified 10 EGFR in NSCCL and 7 KRAS mutations on LBC stored material.
  
  
  CONCLUSIONS
  Peritoneal cytology is an adjunctive tool in the surgical management of tumors mostly gynecological cancers. LBC maximizes the application of ancillary techniques such as ICC and molecular analysis with feasible diagnostic and predictive yields also in controversial cases.
authors.affiliation: Division of Anatomic Pathology and Histology - Università Cattolica del Sacro Cuore, "Agostino Gemelli" School of Medicine, Rome, Italy.
authors.forename: Esther
authors.initials: E
authors.lastname: Rossi
authors.affiliation: Division of Anatomic Pathology and Histology - Università Cattolica del Sacro Cuore, "Agostino Gemelli" School of Medicine, Rome, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Bizzarro
authors.affiliation: Division of Anatomic Pathology and Histology - Università Cattolica del Sacro Cuore, "Agostino Gemelli" School of Medicine, Rome, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Martini
authors.affiliation: Department of Pathology, University of São Paulo School of Medicine, Sao Paolo, Brazil.|Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.|ICVS/3B's Laboratory of Medical Investigation (LIM)- PT Government Associate Laboratory, Braga/Guimarães, Portugal.|Molecular Oncology Research Center, Barretos Cancer Hospital, Pio XII Foundation, Barretos, Brazil.
authors.forename: Adhemar
authors.initials: A
authors.lastname: Longatto-Filho
authors.affiliation: Medical Faculty, Porto University, Porto, Portugal.|Laboratorie National de Sante, Luxembourg, Luxembourg.
authors.forename: Fernando
authors.initials: F
authors.lastname: Schmitt
authors.affiliation: Gynecological Oncology, Catholic University, Rome, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Fagotti
authors.affiliation: Gynecological Oncology, Catholic University, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Scambia
authors.affiliation: Division of Anatomic Pathology and Histology - Università Cattolica del Sacro Cuore, "Agostino Gemelli" School of Medicine, Rome, Italy.
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Zannoni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001202:Ascitic Fluid / Q000166:cytology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000473:pathology; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003581:Cytodiagnosis / Q000379:methods*; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D005833:Genital Neoplasms, Female / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010537:Peritoneum / Q000166:cytology*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D055815:Young Adult
chemical_list: C117307:KRAS protein, human; C512478:EGFR protein, human; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras)