Apicopleural Thickening: Causes, Symptoms & Lung X-ray Interpretation

Apicopleural thickening is a radiographic finding of pleural/pleuroparenchymal thickening at the lung apices. Seen as a hazy, linear, or irregular opacity at the lung apex on chest X-ray or CT.

Common Causes

• Tuberculosis (active or prior): Classic cause; apical scarring (Simon focus).
• Fungal infections: Histoplasmosis, coccidioidomycosis, cryptococcosis.
• Sarcoidosis: Granulomatous inflammation.
• Radiation fibrosis: Post-thoracic radiotherapy.
• Asbestos exposure: Pleural plaques, fibrosis.
• Organizing pneumonia / prior infection.
• Connective tissue disease: Rheumatoid arthritis, SLE.
• Malignancy: Rare; apical tumor (Pancoast) or metastatic pleural involvement.

Clinical Significance

Often incidental. Requires correlation with history, symptoms, labs (TB testing, ACE, serologies), and usually CT for characterization. Stable, asymptomatic findings in a known TB/fungal history may need only monitoring. New or progressive thickening warrants investigation for malignancy or active disease.