摘要Background Pulmonary embolism (PE) is rare and seldom considered in adolescent patients; however it occurs with a greater frequency than is generally recognized,and it is a potentially fatal condition.The aim of the current study was to understand its epidemiology,clinical features and the cause of delay of its diagnosis in adolescents.Methods A retrospective analysis of nine adolescents with acute PE admitted to the Peking University Third Hospital over the past 16-year period was performed.The epidemiology,clinical features and risk factors of the adolescents were described and compared with those of adults and elderly patients.The time to diagnosis and misdiagnosed diseases were analyzed.Pretest probability of PE was assessed retrospectively by the Wells score and revised Geneva score.Results The incidence of PE was 43.6 per 100 000 hospitalized adolescents in our hospital.The incidence of PE in adolescents was much lower than that in adults and PE is diagnosed in about 1/50 of elderly people.The clinical features in adolescents were similar to those in adults.But fever and chest pain were more common in adolescents (P＜0.05).The major risk factors included surgery,systemic lupus erythematosus (SLE),thrombocytopenia,long-term oral glucocorticoids and trauma.The mean diagnostic time was (7.8±8.4) days.Six cases had a delayed diagnosis.The mean delay time from symptom onset to diagnosis was (11.0±8.8) days.The time of presentation to diagnosis in patients initially admitted to the emergency department was less than one day,and was much shorter than the time in outpatients,(9.4±7.5) days.Most of the patients were initially misdiagnosed with a respiratory tract infection.Most patients' values of Wells score or revised Geneva score were in the moderate or high clinical probability categories; 88％ by Well score vs.100％ by revised Geneva score.Conclusions PE was seldom considered in the adolescent patients by physicians,especially outpatient physicians,so the diagnosis was often delayed.If adolescent patients complain of dyspnea or chest pain or syncope with/without fever,and they had risk factors such as surgery,thrombocytopenia and trauma,PE should be considered and included in the differential diagnosis.