Spontaneous pneumomediastinum in adolescents

Spontaneous pneumomediastinum （SPM）, reported firstly by Hamman in 1939, is an uncommon, and usually benign, and self-limiting clinical disorder found in young people often without apparent precipitating factors or diseases. The predominant symptom of SPM is the acute onset of retrosternal chest pain. Because of its low occurrence, and its mild intensity, the diagnosis of SPM can be easily missed. We have reviewed our hospital records for the past five years （about 100 000 in-hospital patients and 90 000 emergency patients） and found only two cases of SPM.