- An unusual case of CSF fistula and tension pneumatocele developing in a patient 22 years after a severe craniocerebral injury is reported. The patient had been asymptomatic during this long interval, but immediately after a minor head trauma massive rhinorrhea and diffuse pneumocephalus occurred. This was followed by the development of bifrontal tension pneumatocele with intracranial hypertension and neurological deterioration. The patient recovered after closure of the CSF fistula. The pathophysiological mechanism of this rare condition and the pertinent treatment are discussed.