[Post-traumatic retroligamentary pneumatocele. Apropos of a case].

A case-report of a 17 year-old man admitted for thoracic trauma associated with a vertical air and fluid collection located behind the pulmonary ligament raises the question of the exact nature of retroligamentary pulmonary pneumatoceles. They may be intraparenchymatous pneumatoceles or simple loculated pneumothorax but whatever the actual lesion, exact recognition of this radiological image avoids drainage and operation. This lesion resolves spontaneously within several weeks.