AB 28. Evaluation of pleural effusion at first diagnosis of lung cancer

Background: Pleural effusion is a common finding at first diagnosis of lung cancer and occurs in 7% to 30% of patients. 50-75% of those effusions are malignant.
Material and patients: We reviewed the files of 126 patients with lung cancer at our department and specifically the patients’ and disease’s characteristics concerning the presence or absence of pleural effusion as well as the correlation of those characteristics with pleural fluid’s features.
Results: 89% of patients were males with a mean age of 66 years. 95% were smokers and 27% of them had pleural effusion. Cough was the most common symptom (51%), followed by dyspnea (33%) and chest pain (19%). Dyspnea and chest pain were significantly more frequent in patients with pleural effusion 56% vs. 25% (P=0.002) and 38% vs. 12%, (P=0.001). The majority of patients with pleural effusion had adenocarcinoma (56%) and lower lobe malignancies were more often associated with pleural effusions. Most of the patients with pleural effusion (71%) had also other metastasis compared to 52% of patients without pleural effusion. Pleural fluid was an exudate in 100% of patients with a lymphocyte predominance in 59%, eosinophilic predominance in 26% and low pH (<7.30) in 29%. Pleural fluid cytology was positive in 65% and in 100% of all effusions with low pH. The prevalence of pleural effusion was not affected by age, gender or number of py.
Conclusions: Patients with adenocarcinoma, lower lobe malignancies and other metastatic lesions presented more often with pleural effusion. Approximately one quarter of patients with effusion had an eosinophilic pleural fluid and pleural fluid cytology was positive in all effusions with a pH value lower than 7.30.