Spontaneous pneumatocele and pneumocephalus associated with mastoid hyperpneumatization.

We present a case of spontaneous pneumatocele and pneumocephalus associated with mastoid hyperpneumatization. Collections of air such as these are normally due to injury or surgery, and more rarely, infection or tumor; exceptionally they may be spontaneous. The patient in question complained of a progressively enlarging retroauricular mass which increased in size on Valsalva maneuvers; he had no other symptoms. The etiology, skull X-rays, computed tomography and follow-up after surgery are shown here.