The radiographic air crescent sign is seen in several clinical conditions (1, 2). Angioinvasive aspergillosis is the most common cause of this sign in the immunocompromised host (3, 4). We report the case of a patient with acute lymphoblastic leukemia who developed the air crescent sign as a result of Staphylococcus aureus lung infection.
Published: Ann Intern Med. 1992;116(11):910-911.