Pleural lymphocyte-rich transudates in cats

Area of Science:

• Veterinary Medicine
• Cardiology
• Oncology

Background:

• Non-chylous lymphorrhagic pleural effusions in cats are transudative effusions with lymphocyte predominance.
• These effusions lack chylomicrons, distinguishing them from true chylous effusions.
• Anecdotal evidence suggests an association with feline cardiac diseases, but lacks robust study.

Purpose of the Study:

• To investigate the association between non-chylous lymphorrhagic pleural effusions and the primary underlying disease in cats.
• To determine the prevalence of cardiac disease and other conditions associated with this effusion type.
• To propose a more accurate terminology for these effusions.

Main Methods:

• Retrospective selection of feline non-chylous lymphorrhagic pleural effusions over three years.
• Inclusion criteria: transudative effusions with lymphocyte predominance on cytology.
• All selected cases underwent thoracic imaging, including echocardiography.

Main Results:

• Thirty-three cases met the inclusion criteria.
• Cardiac disease was present in 23 cases (69.7%).
• Mediastinal lymphoma, carcinoma, or thoracic mass was found in eight cases (24.2%).
• One case each of thymoma and pyothorax sequela were identified.

Conclusions:

• Lymphocyte-rich transudate may be a more appropriate term than non-chylous lymphorrhagic effusion.
• The findings suggest a strong association with cardiac disease or intrathoracic neoplasia in cats.
• Early identification of this effusion type should prompt a thorough search for these underlying conditions.