Answer:
Swyer-James syndrome.
Discussion:
The Swyer-James syndrome (less desirable synonyms include McLeod's syndrome, unilateral emphysema, unilateral lobar emphysema, and unilateral hyperlucent lung) is characterized by predominantly unilateral imaging of Bronchiolitis Obliterans. It is the result of lower respiratory tract infection, usually due to viruses, Mycoplasma organisms, B. pertussis, or tuberculosis, occurring in infancy or early childhood.
Damage to the terminal and respiratory bronchioles leads to incomplete development of alveoli. It is characterized by unilateral hyperlucency of a lung, lobe, or segment, associated with decreased size of associated pulmonary arteries. The volume of the affected lung often is decreased because of abnormal development, but may be normal or increased. Areas of atelectasis and bronchiectasis may be associated. Air trapping is visible on expiratory radiographs. Patients usually are asymptomatic, and the abnormality is detected incidentally. However, dyspnea or recurrent infections may be associated. Ventilation-perfusion scans show matched defects.
Most patients are asymptomatic adults at the time of diagnosis, and the condition is often detected incidentally on a radiograph or CT performed for other reasons. Less commonly, patients present with recurrent infections or dyspnea.
Contributed By:
Dr. Karunakaran M. Kalathi MD, Dr. Arun Chelladurai MD
Consultant Radiologists, Aarthi Scans, Thirunelveli, Tamilnadu, India
Swyer-James syndrome.
Discussion:
The Swyer-James syndrome (less desirable synonyms include McLeod's syndrome, unilateral emphysema, unilateral lobar emphysema, and unilateral hyperlucent lung) is characterized by predominantly unilateral imaging of Bronchiolitis Obliterans. It is the result of lower respiratory tract infection, usually due to viruses, Mycoplasma organisms, B. pertussis, or tuberculosis, occurring in infancy or early childhood.
Damage to the terminal and respiratory bronchioles leads to incomplete development of alveoli. It is characterized by unilateral hyperlucency of a lung, lobe, or segment, associated with decreased size of associated pulmonary arteries. The volume of the affected lung often is decreased because of abnormal development, but may be normal or increased. Areas of atelectasis and bronchiectasis may be associated. Air trapping is visible on expiratory radiographs. Patients usually are asymptomatic, and the abnormality is detected incidentally. However, dyspnea or recurrent infections may be associated. Ventilation-perfusion scans show matched defects.
Most patients are asymptomatic adults at the time of diagnosis, and the condition is often detected incidentally on a radiograph or CT performed for other reasons. Less commonly, patients present with recurrent infections or dyspnea.
Contributed By:
Dr. Karunakaran M. Kalathi MD, Dr. Arun Chelladurai MD
Consultant Radiologists, Aarthi Scans, Thirunelveli, Tamilnadu, India