Lung Carcinosarcoma Masked by Tracheobronchial Aspergillosis.

Tracheobronchial aspergillosis is a form of invasive aspergillosis limited to the airways. Its presence usually indicates an immunocompromised status or local dysfunction of airway immunity. We herein report a case of lung carcinosarcoma masked by tracheobronchial aspergillosis and discuss the clinical manifestations, diagnostic procedures and treatment of such cases. Tracheobronchial aspergillosis may also mask endobronchial carcinoma, leading to difficulties in determining the diagnosis and selecting subsequent treatment. Bronchoscopy is crucial for obtaining a definitive diagnosis and confirming the treatment. In particular, the combination of intravenous antifungal drug administration, localized antifungal application and interventional bronchoscopy is effective. Nevertheless, clinicians should always investigate the underlying disease carefully, including the potential occurrence of lung malignancy.