[Compression pneumatocele of the lacrimal sac].

Case report on a 39-year-old man who for five years suffered from a recurrent, firm, crepitant swelling in the medial canthal region after coughing and sneezing. The swelling could be eliminated by digital compression. During a severe bout of sneezing a walnut-sized swelling suddenly occurred which could not be eliminated by compression. Echographic and intraoperative findings confirmed the diagnosis of a large, diverticulous pneumatocele that had compressed the lacrimal sac to such an extent that the entrapped air could not escape. Endoscopy of the nose revealed a wide nasolacrimal ostium, without a Hasner's valve. It was thus possible for air to flow back into the lacrimal drainage system from the nasal cavity.