Bronchial cast hiding a lung cancer

A 70-year-old man was admitted for severe hypoxia, haemoptysis and cough. Chest-X-ray and CT-scan indicated a right-lower-lobe collapse. Bronchoscopy showed its occlusion by whitish dense mucus. Aspiration revealed a Bronchial Cast (BC) and a stenotic and inflamed orifice of the right-lower-lobe-bronchus which was biopsied. Histopathologic examination of BC showed fibrin with lymphocytes and neutrophils, and, surprisingly, also the presence of lung cancer. Although the association between BC and benign, myxoid-soft-tissue, tracheobronchial tumors has been described, the association with lung cancer has not previously been reported, and it remains unclear whether it is causal or casual.