The Role of Liquid Based Cytology and Ancillary Techniques in the Peritoneal Washing Analysis: Our Institutional Experience

Abstract

BackgroundThe 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).MethodsWe 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.ResultsThe 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.ConclusionsPeritoneal 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.

Are we ready to develop a tiered scheme for the effusion cytology? A comprehensive review and analysis of the literature

“…Seventy‐one studies were designed as a cohort, and nine were case‐control studies . Thirty‐three studies explicitly mentioned that the subjects were recruited consecutively …”

“…In two studies, touch smears were assessed, and in the rest of the studies, the smears and/or cell blocks were prepared from the sediments after centrifuging the serous fluid samples. The cytologic evaluation was performed on only smears in 43 and on both smears and cell blocks in 10 studies . In another 10 studies, cell blocks were prepared in addition to smears when the amount of serous fluid was sufficient …”

Quantitative Proteomic Analysis Identifies AHNAK (Neuroblast Differentiation-associated Protein AHNAK) as a Novel Candidate Biomarker for Bladder Urothelial Carcinoma Diagnosis by Liquid-based Cytology

“…After scraping off of all cytological material within an encircled spot, our single-shot MS analysis achieved identification of a total of 4,839 proteins in a relatively short time without fractionation, which is a comparable depth of proteome coverage to that reported in a previous study (29). Carvalho et al performed LC-MS of conventional bronchial cytology pellets obtained by centrifugation, unlike our harvesting of cellular material from one liquid-based cytology slide from each patient, which can maximize the application of ancillary tests, as well as preserve residual samples for the preparation of additional slides for further molecular analysis, unlike pellet-based testing (30). The harvest of cells directly from cytology slides is still challenging because of the unique characteristics of sample fixation and the limited number of cells from each cytology slide as opposed to FFPE-or FACs-based sorted samples, which are replicable for preparation in proteomic analysis.…”

Yield of peritoneal cytology in staging patients with gastric and gastroesophageal cancer

“…17 Other institutions have also highlighted improvements in the sensitivity and specificity of peritoneal washings from using a wide range of markers. 40 Recent reports have indicated that the detection of carcinoembryonic antigen messenger RNA by reverse transcriptionpolymerase chain reaction is useful for evaluating subclinical tumor cell dissemination in peritoneal lavage fluid. 41 Also, additional gene mutational assays may corroborate the role of cytology to confirm malignancy but also to add prognostic parameters to the patient outcome.…”

“…Our center has investigated molecular testing when cytology material is the only specimen source available and reporting high efficiency using cytology specimens for molecular testing to detect EGFR or KRAS mutation in patients with lung cancer . Other institutions have also highlighted improvements in the sensitivity and specificity of peritoneal washings from using a wide range of markers . Recent reports have indicated that the detection of carcinoembryonic antigen messenger RNA by reverse transcription‐polymerase chain reaction is useful for evaluating subclinical tumor cell dissemination in peritoneal lavage fluid .…”