Malignant pleural effusions with unknown primary sites: A 6 years cytological study

Introduction: Malignant pleural effusion is an important complication found in patients of advanced cancers and lead on to exudative effusions. Not much data is available regarding malignant pleural effusions with unknown primary sites so we had conducted a retrospective study to highlights the primary sites in cases of malignant pleural effusions. Materials and Methods: The present study was conducted at a tertiary care centre at Ludhiana, Punjab. Retrospective analysis of case records of 104 patients, diagnosed as malignant pleural effusions on cell cytology out of 2948 cases of pleural fluids during a 6 years period (2012 to 2017) was done and the results were analysed to assess the causes and various primary sites of malignant pleural effusion. Results and Conclusion: A total of 104 pleural fluid samples were found to be positive for malignancy out of 2948 cases of pleural fluids during the study period time. Lung carcinoma was found to be the most common cause of malignant pleural effusion. On morphology, adenocarcinoma was the most common type of cytological diagnosis in all pleural effusions. Unknown primary malignancies presented as pleural effusions in many cases with no specific signs & symptoms. Cytological study can reveal the morphological diagnosis & clinch the primary site of origin in more than 50% of cases. Cytological analysis of pleural fluid should be the initial diagnostic approach to diagnose malignant pleural effusions and tapped effusions must always be sent for cytological stud