Air Crescent Sign: A Rare Presentation of Varicose Bronchiectasis with Hemoptysis

Abstract

The most common cause of the air crescent sign is aspergilloma resulting from saprophytic aspergillosis. The fungal ball consisting of condensed hyphae can vary in both size and number. Although saprophytic aspergillosis can be asymptomatic, patients may occasionally experience severe, life-threatening hemoptysis. Other causes of the air crescent sign include pulmonary hydatid cysts; lung colonization by other fungi; Rasmussen aneurysms in a tuberculous cavity; lung abscesses; bacterial necrotizing pneumonia caused by Staphylococcus aureus, Klebsiella pneumoniae, or Pseudomonas aeruginosa; and cavitating neoplasm of the lung. Bronchiectasis has not yet been reported as a cause of the air crescent sign. In this paper, we present a case of varicose bronchiectasis complicated with massive hemoptysis; a chest computed tomography (CT) scan of the patient showed the air crescent sign. Clinicians should therefore be aware that while there are several well-known causes of the appearance of the air crescent sign in a chest CT scan, varicose bronchiectasis complicated with severe hemoptysis should be considered as a diagnosis if rapid changes in the image occur during the follow-up period.