A case of petrous ridge meningioma manifested as pneumocephalus followed by Eustachian tube insufflation

: A 50-year-old female, who had a headache after Eustachian tube insufflation for her ear congestion, came to our hospital. CT and MRI revealed pneumocephalus and petrous ridge meningioma which destroyed petrous bone and air cells. Eustachian tube insufflation was considered to make the air coming into the middle ear, mastoid air cell and then into the intracranial space destroying the tumor. At surgery, there was subdural hematoma around the tumor. Total removal of the tumor and the hematoma membrane was performed. Histologically, the tumor was transitional meningioma and the cluster of meningioma cells were noted in the subdural hematoma membrane.