Summary Introduction Spontaneous meningocele or meningoencephalocele of the temporal bone are very rare. Mostly they are result from otologic surgery or head trauma. Spontaneous meningoencephalocele may occur mostly in the epitympanum or mastoid antrum. It could be a result of pathologic obesity. Often it could be misdiagnosed because of less symptomatic. The most expected symptoms could be: unilateral conductive hearing loss with middle ear effusion, pulsatile tinnitus or CSF leak. Material and methods We present a case of 61 year old, obese woman with spontaneous meningoencephalocele of the left temporal bone. The patient presented symptoms of conductive hearing loss with fullness in the left ear and pulsatile tinnitus. The imagine study such as CT scan and MRI showed a dehiscent areas in the tegmen at the right side and meningoencephalocele protruding into the left mastoid cavity on the left side. Results After complete diagnosis we preformed surgery. A mastoidectomy of the left temporal bone was done and the meningoencephalocele tissue was encountered. The bony defect and CSF leak was closure. The patient was released from pulsatile tinnitus and fullness in the ear, but a component of hearing dysfunction is still present. Conclusions Spontaneous meningoencephalocele of the temporal bone may occur in an obese patient. The most finding will be a middle ear effusion and conductive hearing loss with pulsatile tinnitus. The combination of CT and MRI will help in proper preoperative diagnosis. The operation include transmastoid, middle cranial fossa repair or combination of both. The multi layer closure of bony defect is very important to avid CSF leak.
