Spontaneous pneumatocele during radiation of a giant meningosarcoma.

A man, aged 66 years, sustained a pneumatocele after radiotherapy for a frontabasal meningeal sarcoma. There was improvement initially, but a fall was experienced without injury to the head and the condition worsened. X-rays of the skull revealed a pneumatocele which was treated conservatively and disappeared within 4 weeks. The literature on spontaneous pneumatocele is reviewed briefly and the etiology discussed.