Tympanic Membrane Pneumatocele from Auto-insufflation.

A tympanic membrane pneumatocele represents a rare cause of an external auditory canal mass. The diagnosis can be made clinically via history, palpation, and otoscopy during auto-insufflation, potentially avoiding further diagnostic testing. Depending on the etiology, resolution can occur after lifestyle modification; however, further interventions may definitively treat the condition if so required.