Low power: DQ stain
Numerous lymphocytes present
High power: DQ stain
Abundant small lymphocytes present
Note: few scattered mesothelial cells and histiocytes
High power: DQ stain
Abundant small lymphocytes together with mesothelial cells and histiocytes
Features
Cellular features
• Usually cellular sample
• Numerous small lymphocytes
Notes
• Lymphocytic effusions are non-specific but may be seen in association with malignancy or infections. Immunoperoxidase stains or flow cytometry or microbiologic culture studies may be necessary to rule out malignancy/ infection.