Sphenoid wing meningioma: Complex cases

Case based discussions with panel Q&As
Sphenoid wing meningioma: Complex cases
Presenter: Anouk Borg.

My name is Anouk, I’m a neurosurgeon. At the moment I’m working in Oxford and thank you Mr. Verity for the invitation. I have no disclosures to make. Since this is the last talk of the day, I’m going to make it a bit interactive and ask the audience for comments. I’m going to go through three complex cases, and the reason why these cases are complex is because they required the expertise and the involvement of multiple specialities from neuroradiology, neurosurgery, ophthalmology and radio oncologists.

I’m going to show three cases of sphenoid wing meningiomas that required three types of different management, they were challenging in making the diagnosis, symptom control and in their management.

Case 1

The first case is a 35 year old gentleman who presented with a five week history of left-sided proptosis. He had a childhood history of medulloblastoma, for which he underwent posterior fossa surgery, and also received radiotherapy, and at the time he would have probably received whole brain radiotherapy. At the time of presentation to the ophthalmologists, he had normal visual acuity and normal fields, despite the prominent proptosis he had no diplopia.

This was his MRI which shows, an extrinsic lesion which has both an intra orbital and intracranial component. Initially this was suspected to be a radiation induced sarcoma, given the history of radiation, so he underwent a biopsy of the orbital component and the histology revealed that this was actually a meningioma. It was at that point that he was referred to neurosurgery.

He was discussed in the skull base MDT and the option of surgery was offered to the patient and because of the two different components of the tumour, a combined approach by a neurosurgeon and orbital surgeon was performed. The histology done revealed WHO Grade I meningioma with an additional comment that there was widespread bony invasion, even though this was a Grade I meningioma. This is an interpretive picture of the approach, which is a pterional approach as described earlier by Mr. Kitchen, but it’s an extended pterional approach with osteotomies removing the zygoma to have better access to the orbit. Postoperatively he had a small residual and the orbital component in the supramedial aspect.

On follow-up a few months later, unfortunately this residual was seen to increase in size. Fortunately the intracranial component was clear. Because of this increase in the size of the residual, his visual acuity starting to drop slightly, his proptosis was also noticed to be slightly worsening and also given the histological features of the bone invasion, radiotherapy was considered. When he was discussed in the MDT, the neuro-oncologist felt that the residual was up against the globe and the tolerance of which was 45 Gy and ideally, meningioma should receive at least 50 Gy, so the MDT decision was to tackle that residual with further surgery. Recently he’s then undergone an anterior orbitotomy through an upper lid skin crease wound.

Postoperatively his vision remains stable and his proptosis has improved; he’s still waiting the three-month post-op scan, however intraoperatively it was felt that all the tumour was completely removed. Radiotherapy will be considered if there is any further re-growth.

The questions that can arise from discussing this case are:
-This patient underwent three operations; we had the biopsy, the craniotomy and then the orbitotomy, Could all tumour have been removed from one operation?
-As things stand at the moment, Should he receive radiotherapy straight away to the tumour bed or should we wait and only offer radiotherapy if there’s any re-growth?
-What should the frequency and length of surveillance be and should it be annual MRI scans, is that sufficient and for how long?
Q & As section- Case 1

Comment
I think this was one of the cases which Katherine showed earlier. There was a differential diagnosis here and with the speculation of the bone and so on, that was felt that it could possibly be a sarcoma and hence the biopsy, so that was the transorbital biopsy presume. I suppose the question is, there was some small amount of residual in the orbit and if there hadn’t been, then he’d have only had one operation. But as it was, I think it’s the correct thing to have done, to proceed to the second surgery, particularly as that residual had grown. My view is that it’s shown to be wise with bony disease and so I think radiotherapy is not an unreasonable thing to do now.

Question 1
Could I ask a silly question for either to our radiotherapy Gillian or to Neil? These posterior fossa tumours, how come they are getting tumours so far away? is it scatter zone? And if so, why isn’t it occurring at their occipital entry zone where it’s much more high radiation dose?

Answer
As I think this person had is a tumour that’s still, apart from in youngest children under 3 years of age, is treated with whole brain and spine radiotherapy. Still now, there is higher dose to the posterior fossa but they would still now as he receive appreciable tumour dose to the whole brain.

One thing about should radiotherapy be delivered right away? You’ve mentioned that ideally, the retina would be kept below 45 Gy and ideally you’d give at least 50 Gy to meningioma. But the one thing you haven’t mentioned, is that he’s probably had at least 30 Gy already to the retina, and while there is some recovery over time, it’s not complete, so that’s a consideration. There will have been obviously dosed to the optic nerve as well, so that will limit you even more in terms of getting in a radical dose.

My own view is if you’ve managed to do fairly good surgery, you might at least initially observe and see whether it’s regrowing or not, because there may be some either risk to vision or your dose will be suboptimal.

Question 2
Do you think Gillian it’s inevitable to regrow? Let’s be honest, it’s a pervasive disease, it’s been operated, probably If I’d done the biopsy, initially I may well have taken the whole of the orbital component to give, so the pathologist doesn’t say “small piece of tissue with handling artifacts” they can have a bottle full of the stuff and then if it turns out to require involvement or surgery for the intracranial component, then you can sort of address that, but it’s going to come back eventually. The question is when and what you do then.

Answer
I think the problem with any of these meningiomas the Grade Is, bone invasion doesn’t make you a higher grade. It’s always difficult to know what the limits of it are and we always try and include hyperostosis and then we put a margin on for possible microscopic disease but you never really know whether that’s enough in a particular case, I think they probably will have recurrence that’ll need to be managed.
Case 2

The next case is a 38 year old lady who presented in 2003, with right-sided proptosis and headaches but had no visual symptoms at the time.

Now one of the challenges of this case was that it was in 2003 and the images were still on film back then, and she was managed by another surgeon who’s now retired, so she was inherited more recently to us. At the time in 2003 given the MRI had showed bilateral sphenoid wing meningiomas. She underwent a right orbito-zygomatic approach for resection of the right-sided meningioma and as well as lateral orbital wall decompression; histology there showed it was a WHO Grade II.

Unfortunately a few months after the first operation, she started to develop blurring of vision in the left eye and she also started to have constricted visual fields and was only able to finger count. Her MRI at the time was reported as showing an increase in size of, this time, the left-sided meningioma and this was abutting the optic chiasm. So she underwent another operation, this time on the left and even after that, her vision continued to deteriorate.

This was the first scan that was available on film and this was after her second operation. As you can see the right-sided meningioma is intraosseous as well and that’s why initially she has undergone surgery on that side; and the left side seems to have been adequately surgically decompressed.

In 2004 after her operation, she remained with only light perception in the right eye and 6/9 vision on the left, but she had a visual field defect on that side.

In 2005 she underwent Gamma Knife radio surgery, where she received 45 Gy in 25 sessions. After that she started to develop galactorrhea and symptoms of hypopituitarism, and is thought likely be be from tumour infiltration of the sella, although it could also have been radiotherapy related. She also started to develop severe trigeminal neuralgia on the left side, which is thought to be from tumour infiltration, possibly Meckel’s cave and the cavernous sinus.

In 2007 visual acuity and also her visual fields on the left side continued to deteriorate.

In 2009 there wasn’t any further deterioration so she has continued with imaging surveillance.

Over the years, the left-sided meningioma, which was treated with surgery and Gamma Knife, seems to be under control. The right side, as you might notice, the bony invasion seems to become more prominent and that was actually what was bothering the patient the most, it was cosmetically not very nice. Her trigeminal neuralgia was controlled with medication.

In 2014 she underwent superficial drilling of the hyperostotic bone, which was mainly to provide her with comfort and also to improve her cosmetic appearance. Although some fluctuation in her vision overall over the years it remained stable until this year, when she started reporting further deterioration in her vision. She had another MRI scan, which was reported as not showing a compressive effect of the left optic nerve but it was subtle enhancement, which was not deemed to be a surgical target.

This is her most recent MRI scan and so she’s still blind on the right side and on the left side, which is the side we were trying to preserve her vision, seems to be an enhancing component around the track the optic nerve. So the oncologist recommended that we obtain a Gallium Dotatate PET/scan, which shows basically intense uptake on the right side still, and also on the left side the uptake was not intraorbital. So our oncologists went back and reviewed her old Gamma Knife plan and they found out that she had already received full dose of radiation to the retina, therefore further radiotherapy was not deemed possible and they told her it’d be more likely to make her vision worse.

Currently the situation is that she remains on full hormone replacement and analgesia for her trigeminal neuralgia, she continues to be monitored with imaging surveillance and visual fields, however further treatment is unlikely to be of benefit.

So the discussion points are:
-How come she still developed visual loss despite having adequate decompression?
-What is the cause of the ongoing visual deterioration?
-Is it related to previous radiotherapy or is it just the nature of the disease?
-Is there any point of continuing surveillance imaging if we cannot offer further surgery or further radiotherapy?

Q & As section- Case 2

Comment
It seems quite end stage in terms of her orbital disease, so I’m not sure anything here’s going to help particularly. I don’t think she couldn’t have had Gamma knife given in multiple fractions, it’s either Gamma knife or it’s not Gamma knife, that needs to be clarified in terms of radiation dose.

Question 1
So on the current imaging, is there any compression of the left optic nerve?

Answer
No, it was not felt that there was a compressive mass, there could be, tumour possibly spreading along the optic nerve sheath but nothing that could be seen.

Comment
What was truly micro vascular disease and finally the optic nerve is suffered to the point, it’s like extreme glaucoma you’ve only got so many nerve fibres left and they’re just giving up in terms of their ischaemia or metabolic stress in this case. And it I don’t know of any way of helping it really.

Case 3

Last case is quick, a 41 year old lady presented three days after giving birth to her second baby with throbbing headaches, blurring of vision in her right eye, periorbital swelling, and very debilitating diplopia.

The referring team started her on dexamethasone and she noticed a mild improvement in her symptoms. We saw her in clinic, she was a very anxious lady expecting that she will be offered surgery, but over the next few weeks and months her visual acuity was improving, but she was found to have six millimetre relative exophthalmos.

This was her scan, which shows that she has quite a bit of an intraosseous component to what’s thought to be a sphenoid wing meningioma. She was discussed in the skull base MDT and it was deemed that given that she was in the post-partum period and the vision was normal, not affected, and her diplopia had settled with steroids, we offered her an interval scan after six weeks, she looked more or less the same.

We advise that we will continue for the time being with conservative management and we will continue with regular ophthalmology assessment and annual surveillance. This is her most recent scan which was reported as being stable compared to a few months ago.

The discussion points would be:
-What’s the role of dexamethasone in the management of sphenoid wing meningioma?
-Which was already touched upon earlier, Should surgery be offered acutely at her time of presentation or even now that we know about the tumour but her visual acuity is normal?
-And she was very concerned about the proptosis, is that enough of an indication for surgery?

So I’ll move on to the key points of this talk which are; although all three cases showed sphenoid wing meningiomas, the management was different and therefore this should be tailored to the individual patient. Management should be guided by the clinical picture rather than just by imaging. Multidisciplinary approach is key.

Q & As section- Case 3

Comment
I think conservative management plan initially, at least initially I think we all agree with. In fact in retrospect she probably had that meningioma and some degree of proptosis for a while, I would have thought.

Question 1
Can I just quickly ask, what was the basis of the response to dexamethasone, do you think? Was it a presumed inflammatory component?

Answer
It was immediately after that she gave birth that her symptoms have shown up, so it seemed to be some inflammation and dexamethasone would help with that, that’s our theory anyway. It was only for a 14-day course that she had, so she wasn’t on it long term.