Left-sided Neck Swelling: An Unusual Presentation of a Rare Disease.

Pneumomediastinum describes air infiltrating into the soft tissues of the mediastinum. It may be classified as spontaneous or secondary. Spontaneous pneumomediastinum is a rare disease, which usually resolves without intervention. The acute onset of chest pain is the most common presenting complaint.  This article presents a case of spontaneous pneumomediastinum in a 19-year-old man with a short history of rapidly enlarging, painless swelling to the left side of his neck, followed by a discussion of the literature. The diagnosis was made following chest x-ray (CXR) and computed tomography (CT). There was no history of any precipitating event or any risk factors. He was managed conservatively and discharged with outpatient follow-up.  Management of spontaneous pneumomediastinum continues to vary and may benefit from the development of guidelines to standardise management in the future.