Pleural thickening that is circumferential, nodular, > 1 cm thick, or involves the mediastinal pleura points to malignancy (Leung criteria); the report gives the pattern and extent, and looks for asbestos markers and the primary.
Orient first
- Leung criteria: circumferential thickening, nodularity, parietal thickening > 1 cm, mediastinal pleural involvement (verify).
- Mesothelioma encases the lung and fissures, reducing volume; metastases (lung, breast) are commoner.
- Solitary fibrous tumour: a well-defined pleural mass that may be pedunculated.
Acquire the study
- Contrast-enhanced CT chest in the delayed (~60–90 s) phase for pleural enhancement; PET-CT and MRI for staging mesothelioma.
The manoeuvre
- Post-contrast series: pleural thickness in mm; nodularity; circumferential involvement.
- Mediastinal pleura and fissures.
- Chest wall invasion (fat plane, rib destruction) and diaphragm.
- Calcified plaques (asbestos); ipsilateral volume loss.
- Primary tumour, nodes, and the contralateral pleura.
What confirms it
- Histology (thoracoscopic biopsy).
What licenses you to exclude it
- Smooth thickening < 1 cm without nodularity makes malignancy less likely — it does not exclude it.
The classic misread
- Reading a loculated empyema as pleural tumour — enhancement is smooth and thin in empyema.