Pleural fluid accumulates in the pleural cavity due to various conditions such as infection, malignancy, or systemic disease.

Cytological examination involves microscopic analysis of pleural fluid cells.

Clinical uses include:

Detecting malignant cells (e.g., lung cancer, metastatic carcinoma, mesothelioma).

Identifying infectious causes (e.g., tuberculosis, bacterial infections).

Differentiating between transudative and exudative effusions.

Often performed alongside biochemical tests (protein, LDH, glucose), microbiology, and imaging studies for comprehensive evaluation.

Analyte: Cellular components of pleural fluid.

Normal Result: No malignant cells; presence of normal mesothelial cells and inflammatory cells.

Abnormal Findings:

Malignant cells: Suggest cancer (primary lung tumor or metastasis).

Reactive mesothelial cells: Seen in inflammatory or infectious conditions.

Lymphocytic predominance: Suggests tuberculosis or malignancy.

Neutrophilic predominance: Suggests bacterial infection.

Clinical Use:

Provides a direct cytological evaluation of pleural effusion.

Helps guide diagnosis, prognosis, and treatment planning.

Supports pulmonology, oncology, and internal medicine evaluations.