Misleading Markers: Troponin-Positive Spontaneous Pneumomediastinum Masquerading as Acute Pericarditis in a Young Cannabis User.

Spontaneous pneumomediastinum (SPM) is defined as the presence of free air within the mediastinum without an apparent precipitating cause such as trauma, invasive procedures, or oesophageal rupture. SPM is typically benign and self-limiting but may mimic life-threatening conditions such as myocardial infarction, pulmonary embolism, or aortic dissection. The pathophysiology is most explained by the Macklin effect, where increased intra-alveolar pressure leads to alveolar rupture and dissection of air along bronchovascular sheaths into the mediastinum. Recognized risk factors include intense physical exertion, vomiting, Valsalva manoeuvres, and recreational drug use such as cannabis and cocaine inhalation. Although SPM usually follows a benign course, prompt diagnosis is important to exclude secondary causes such as Boerhaave syndrome or tracheobronchial injury, which carry significant morbidity and mortality if missed. We report the case of a healthy 18-year-old male who developed extensive spontaneous pneumomediastinum shortly after smoking, with a background of prior cocaine use. This case highlights the importance of recognizing SPM in the differential diagnosis of acute chest pain in young adults and reinforces the value of conservative management following thorough exclusion of secondary causes.