Spontaneous pneumomediastinum: experience in 18 patients during the last 12 years.

Objective:: To characterize clinically all of the patients with spontaneous pneumomediastinum (SPM) admitted to an adult pulmonology ward in Lisbon, Portugal.

Methods:: This was a retrospective descriptive study of all adult patients (≥ 18 years of age) diagnosed with SPM between January of 2004 and September of 2015.

Results:: At least one predisposing factor was identified in most (88.