Methods: Between May 2019 and May 2020, a total of 117 patients (43 males, 74 females; mean age: 63.1±18.1 years; range, 18 to 93 years) who had pleural effusion and analysis of pleural fluid were retrospectively analyzed. All patients were evaluated in terms of age, sex, presence of comorbid diseases, approach to the pleural fluid, biochemical values of peripheral blood and pleural fluid, hemogram series of peripheral blood, diagnosis of pleural fluid, and mortality.

Results: Of the patients, 66 (54.5%) were diagnosed with benign pleural effusion and 51 (43.5%) were diagnosed with malignant pleural effusion. Number of cases with known primary malignancy was 54 (46.1%). Immature granulocyte count number and percentage of venous blood in the malignant pleural effusion group was significantly higher than the group with benign pleural effusion (p<0.05).

Conclusion: As a hemogram parameter, immature granulocyte level is an easily applicable, cheap, and a non-invasive method in the outpatient settings.