Can pleuritis appear similar to a pleural effusion on an x-ray?

Pleuritis Can Appear Similar to a Pleural Effusion on X-ray

Yes, pleuritis can appear similar to a pleural effusion on chest x-ray, as acute pleuritis may be accompanied by fluid accumulation that manifests radiographically as an effusion. 1

Radiographic Appearance of Pleuritis

• Pleuritis (inflammation of the pleura) can present with pleural fluid accumulation that appears as an effusion on chest x-ray 1
• The fluid associated with pleuritis is typically exudative and often hemorrhagic, containing variable numbers of erythrocytes, neutrophils, lymphocytes, mesothelial cells, and frequently eosinophils 1
• Acute pleuritis may be detected incidentally on radiographs taken for other purposes, appearing as a pleural effusion 1

Distinguishing Features and Diagnostic Challenges

• On plain chest x-rays, it can be difficult to differentiate between pleuritis with effusion and other causes of pleural effusion 1
• CT scan provides better characterization than plain films and may show:
  • Mild smooth thickening of the parietal pleura in non-infective inflammatory causes of effusion, including pleuritis 1
  • Pleural fluid with possible visceral pleural thickening 1
• Ultrasound can help distinguish pleuritis-related effusions from other causes, as inflammatory effusions may show complex internal septations 1

Clinical Correlation with Radiographic Findings

• Patients with pleuritis often present with pleuritic chest pain and may have a friction rub on examination 1
• The effusion associated with pleuritis may persist for months, present bilaterally, or recur on the same or opposite side 1
• Traces of pleural effusion from pleuritis may be observed years later as a blunted costophrenic angle or as diffuse pleural thickening 1

Diagnostic Approach When Pleuritis is Suspected

• Thoracentesis is essential for evaluating unexplained pleural effusions seen on imaging, as radiographic features alone have poor sensitivity (0.20-0.48) for determining etiology 1
• Analysis of pleural fluid should include:
  • Chemical and microbiological studies 2
  • Cytological analysis to evaluate for reactive mesothelial cells typical of pleuritis 3
  • Differentiation between exudate and transudate 2

Important Considerations and Pitfalls

• Pleuritis with effusion can mimic malignant pleural disease, particularly mesothelioma, making thorough evaluation crucial 1
• The diagnosis of pleuritis-related effusion is often made by excluding other causes of pleural fluid accumulation 1
• Follow-up imaging may be necessary, as non-specific pleuritis can occasionally be the initial presentation of an underlying malignancy in approximately 8.3% of cases 4
• In most cases (91.7%), non-specific pleuritis follows a benign course with spontaneous resolution of the effusion 4

Special Considerations in Asbestos-Related Pleuritis

• Asbestos exposure can cause acute pleural effusion that may be mistaken for other causes of pleuritis 1
• These effusions may be superimposed on long-standing pleural plaques and can lead to diffuse pleural thickening over time 1
• Calcified pleural plaques may be visible on imaging in cases of benign asbestos-related pleural effusion 1