Management of cytological material, pre‐analytical procedures and bio‐banking in effusion cytopathology

Serous effusion fluid is one of the most commonly encountered specimens in routine cytopathology practice. It provides invaluable information about the patient and the clinical status; but to get the most of it, specimen handling and processing must be carried out properly. Cytomorphology is the basis of a successful analysis which should complemented by ancillary tests when needed. A wide spectrum of ancillary techniques ‐ ranging from immunocytochemistry and flow cytometry to different assays of molecular pathology ‐ can be applied to serous effusions. This article describes the acquisition and management of serous effusion fluids, methods for preservation and transportation, different techniques of cytopreparation, application of immunocytochemistry, flow cytometry, and fluorescence in‐situ hybridization ( FISH ), as well as DNA extraction for polymerase chain reaction ( PCR ) and next generation sequencing ( NGS ). Principles of bio‐banking of effusion samples are also discussed which is getting more important in correlation with the developments in personalized medicine.