Expert: Dina Q Goldin, Ph.D. - 4/3/2009

Question
QUESTION: Thank you for your past responses.  Your info has been very helpful.  Is it your belief that an IS behaves the same as an AN??  It is apparent that my tumor is growing both by enhancement on MRI and digressing hearing loss now profound in the affected ear.  Can this grow beyond the cochlear and affect possibly the facial nerve and other structures??  One surgeon told me it usually grows until it encompasses the entire cochlear and produces deafness and then stops.  Have you found this ever to be the case??
Thank you!!

ANSWER: The medical name for AN is "vestibular schwannoma", meaning a shwannoma of the vestibular nerve. The vestibular nerve starts at the cochlea and goes to the brain from there. Shwann cells are the cells that cover the nerves; when they grow out of control, you get a shwannoma. Luckily, schwannomas are benign.

Yours is also a schwannoma, and probably also vestibular, that happens to grow further inside the ear (closer to the cochlear) than is typical.  While progressive hearing nerve is common for ANs, facial nerve is usually not affected since it is not nearby, unless the tumor grows to be gigantic. If the tumor is still small, it is common to wait to see if it stops growing. On the other hand, it is a good idea to continue doing research while you wait. If you've only been consulting with surgeons, you should definitely find some radiosurgeons with experience in Intracochlear Schwannomas, and consult with them too.

---------- FOLLOW-UP ----------

QUESTION: Thanks again for your answer.  I am in the process of trying to schedule an appoint. with a radiosurgeon but he wants another MRI first. The last one was in November 2008.  I've consulted with two well respected neurosurgeons and they both have differing opinions. One feels I should have it removed surgically and not wait a year, 6 months would be fine.  The other feels that it hasn't grown that much in 7 months although some and following could still be an option, also contacting a radiosurgeon possibly for control.  He claims that before I would have to be concerned about invading other structures it would have to fill the entire cochlear and he doesn't feel that has happened.  If I'm going to need surgery I don't want to wait for it to invade other structures either and he mentioned that it could be a hemangioma, many others disagree and with radiation you might not know what you are radiating.  He did recommend that before I subject to surgery to seek yet another opinion.  This is getting exhausting.  In the meantime they all agree that I am losing all hearing fairly rapidly and nothing can be done for this. Removing the entire cochlear what are the chances of still having the pulsatile and second tinnitus that I now experience???  I'm planning on also setting up an appt. at John Hopkins.  Thank you again.

ANSWER: Why does the radiosurgeon want another MRI?  Perhaps he wants to make sure it's not a hemangioma, and the MRI you have is not fine enough?  Otherwise, if he just wants to see where your tumor is and how large it is, a new MRI is not warranted; the one from November 2008 should be fine, especially since it hasn't grown that much in 7 months. However, if you do decide to have radiosurgery, it is true that a radiosurgeon would need a very recent MRI in order to plan their treatment.

As for the statement that "with radiation you might not know what you are radiating" it sounds like a surgeon scare tactic.  A good radiosurgeon, like the ones at John Hopkins, should be able to tell exactly what's going on from an MRI. I strongly recommed consulting them if you want to minimize your risks of post-treatment complications. Surgery gives you a significant risk of facial and other problems afterwards (even if the tumor itself is not touching the facial nerve); with radiosurgery, the chance of these problems becomes much smaller.

---------- FOLLOW-UP ----------

QUESTION: That was the question one of the surgeons asked as to why order another MRI.  The radiosurgeon did not see the actual films, I just mailed the report which identified the intracochlear schwannoma.  I'm just trying to set up an appointment and I had to have this before they would accomodate???  One thing everyone agrees, this is smack in the middle of the cochlear.  It can be interpeted as an enhancement with an inflammatory process.  The one surgeon who suggests removal copied a picture off the computer and I was able to see the circular portion on the good side (left side) the same color as the brain material.  The right side although it appeared about the same in size maybe slightly larger it definitely was white in color.  I have taken your advise and have done some research.  Of course, it is much easier to find info on AN, not that much on an IS but I have found some case histories and info on how they behave. In almost all cases they continue to grow and an MRI may or may not reveal the extent of the growth.  What I have read suggest fractionated radiostatic surgery for AN's to help mimimize damage to healthy surrounding tissue but I read where it takes 6 to 12 months to show signs of necrosis and usually in the center of the tumor. As with any radiation and I have had radiation for BC and thyroid cancer) damage could maifest much later for example in my case equilibrium or the facial nerve from swelling.  And there is still a chance it can continue to grow at some point but it appears to be pretty effective in at least slowing that from what I'm reading.  The tinnitus, I'm assuming as it only damages the tumor and it would still remain on the cochlear,(considering a radiosurgeon can address an IS)would probably remain or possibly become worse???  That would seem logical to me.  Surgical removal may address or at least minimize this possibly although I understand the brain may continue to emit some sound.  Do I have this info right???  I'm waiting to get a call from Hopkins, I've mailed and they have received required info.  She is trying to find the right doctor who can address this. As  I'm writing this I was just scheduled for the end of April with the radiosurgeon. I actually did see another gamma knife specialist before this last progression of symptoms an he could not do anything for me.

Answer
<< The tinnitus [after radiosurgery] would probably remain or possibly become worse???  That would seem logical to me.  Surgical removal may address or at least minimize this possibly>>>

The tinnitus is usually the least of your worries after surgical
removal. The risks from surgical removal are more serious: facial paralysis, debilitating headaches, crippling fatigue.  A significant
portion of AN surgery patients can never return to full-time work
afterwards, if they worked before; a large portion suffer permanent reduction in their quality of life, even if they can work. Our job as patients is to do what we can to minimize the risks of quality-of-life degradation after our treatment. The best way to do so it so have radiosurgery instead.  If you must have surgery, seek the very best team possible, even if it means traveling away from home.

Frankly, it sounds like you are getting too much of your information from surgeons and not enough information from others, such as patients, to balance it out. I suggest that you read patient stories and other pages of the AN Patient Archive (www.ANarchive.org) to get a better idea of what the surgery experience can be like.