Cytologic analysis of body fluids with an emphasis on malignant effusions

Introduction: Fluid cytology, a relatively non invasive technique, throws light on both malignant and non malignant causes of effusions. It especially contributes in cancer research and staging of various tumors. Materials and Methods: This was a retrospective study done over a period of two years from January 2014 to December 2015 in the department of Pathology, Kamineni Academy of Medical Sciences and Research Centre, Hyderabad. The body fluids included in the study were pleural, peritoneal, pericardial and synovial fluids. All other fluids were excluded. The relevant clinical data was noted. Gross, cell count and cytomorphological examinations of fluid were done. Results: Out of 302 cases, pleural fluids, 148 (49.0%) cases, were most common, followed by peritoneal fluid, 125 (41.39%) cases and least common was pericardial fluid, 8 (2.64%) cases. The maximum numbers of cases was in 5th decade. The age range was 3 years to 84 years. Female preponderance was observed with M: F ratio of 1: 1.17. Lymphocyte rich exudates were most common in pleural effusion. In peritoneal and pericardial effusions, transudates were more and suppurative inflammation was predominant in synovial fluid analysis. Over all, malignant effusions constituted 18.54% of effusions. Metastatic adenocarcinoma was the commonest malignancy detected in all body cavity effusions. Conclusions: Fluid cytology is relatively painless, simple, cost effective, rapid technique that yields quick and reliable results. Some cases may present major interpretative challenges to the pathologist. Ancillary studies such as cell count, biochemical, microbiologic evaluation, cell block and immunohistochemistry (IHC) study help in accurate identification of diagnosis.