Quadrigeminal cistern lipoma mimicking intracranial air.

Intracranial lipoma concomitant with traumatic pneumocephalus is very rare and, to the best of our knowledge, there has been no report describing this condition. It may be difficult to distinguish lipoma from intracranial air only with CT, but it is necessary to avoid overtreatment. We report a case of quadrigeminal cistern lipoma mimicking intracranial air in a patient with traumatic pneumocephalus.