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Acoustic schwannoma (translabyrinthine resection)

Case contributed by Dr Bruno Di Muzio


Hearing loss on the left.

Patient Data

Age: 27 years
Gender: Male

MRI demonstrates a solid heterogeneous tumor at the left cerebellopontine angle, enlarging and partially occupying the left internal acoustic canal, exhibiting vivid contrast enhancement and mass effect over the adjacent cerebellar peduncle and pons. The fourth ventricle is partially effaced, however there is no obstructive hydrocephalus. 


CT Temporal bones (preoperative)

Marked enlargement of the left internal auditory canal presumably due to the presence of an acoustic neuroma, although no soft tissue windows have been performed. Cochlea and bony labyrinth are intact. Middle ear structures are normal.

Right petrous temporal structures are normal (not shown).

Note made of high riding jugular bulb bilaterally.

Surgery was performed and the tumour resected and confirmed to be an acoustic schawannoma. 


CT Brain (postoperative)

Previous translabyrinthine approach craniotomy and resection of left acoustic neuroma noted. Overlying mild subcutaneous swelling containing a small volume of gas and surgical clips also noted.

No intra- or extra-axial collection or hemorrhage demonstrated. Grey-white differentiation is preserved. Ventricular size, sulcal pattern and basal cisterns all appear unchanged.

Pneumocephalus has almost resolved. Most of the mastoid has been resected on the left but fluid fills remaining mastoid air cells. Opacification of the left middle ear cavity has been present since the post-operative CT brain.

Partial opacification of the left sphenoid sinus was present preoperatively. No fluid in ethmoid air cells.​



MRI Brain (selected images) - late follow-up

Previous left translabyrinthine resection with fat packing material in situ. Stable gliosis in the anterior aspect of the left cerebellar hemisphere. Linear dural enhancement in the left posterior fossa is unchanged from previous and has no nodularity, compatible with post-operative change. The non-dominant left transverse and sigmoid sinuses remain patent.

Contralateral IAM is normal. Remainder of the brain is within normal limits. No hydrocephalus.

Conclusion: Expected postsurgical changes related to previous translabyrinthine resection of left acoustic schwannoma. No evidence of residual or recurrent tumor.​

Case Discussion

This patient had a histologically proven left acoustic schwannoma that was approached surgically using the translabyrintine technique. Postoperative CT demonstrates the fat pad occupying the resected portion of the temporal bone. Later MRI shows partial retraction of this fat pat and no signs of tumor recurrence. Other common approaches used by this kind/location of tumor are: 

  • retrosigmoid (trans-meatal) (suboccipital)
  • middle cranial fossa
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Case information

rID: 43570
Published: 27th Mar 2016
Last edited: 27th Feb 2020
Tag: rmh
Inclusion in quiz mode: Included

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