Introduction:
Pneumomediastinum is defined as the presence of free gas in the mediastinal space and occurs with varying frequency depending on age.

Aim of the study:
The aim of this study is to report a series of spontaneous pneumomediastina in a paediatric population.

Material and methods:
The study is a retrospective analysis of five clinical cases of pneumomediastina in adolescent patients hospitalised in the Clinical Department of Paediatric Surgery between 2016 and 2018. Two girls and three boys with a mean age of 16.4 years were admitted to the emergency room due to dyspnoea and visible enlargement of neck circumference, which was due to emphysema of soft tissues of the neck. In three patients, chest pain was the predominant symptom. One patient presented with speech difficulties. On admission the general condition of all patients was good. Cardiovascular and respiratory efficiency was reported in all patients. The main symptom suggesting pneumomediastinum was the presence of soft tissue emphysema of the neck. Chest X-ray was performed in all patients as a preliminary examination, confirming the suspicion of pneumomediastinum. Oesophagography was performed in four patients. However, no abnormalities were detected. All patients underwent chest CT.

Results:
Despite extensive changes in CT, no progression of symptoms was observed. There was no indication for surgical intervention in any patient. Complete spontaneous regression was observed in all cases between day 4 and day 21 of the follow-up. Patients were discharged home after 6–10 days of hospitalisation. No recurrence in long-term follow-up was observed. Spontaneous resolution of free gas in the mediastinum was observed in all patients.

Conclusions:
Survival rates of patients with pneumomediastinum of unknown cause that do not require surgical treatment are high and reach about 92.5–100%. In the vast majority of patients, spontaneous resolution is observed. The prognosis is therefore favourable, and the risk of recurrence is low.