Wait & watch option (conservative management)

Introductory comments about acoustic neuroma treatments

The options open to AN patients are basically:

The options open to AN patients are basically:
  • surgery,
  • radiation,
  • watch & wait (no treatment).

Before deciding on the type of treatment you want, ensure that you know all your options.  We recommend that you start with the treatment options page. This page is for patients who are contemplating wait & watch (conservative management). Different pages explore surgical and radiation treatments options.  You are strongly advised to read them all before making any decision.

Reasons to choose wait & watch rather than medical treatment.

  1. Statistically, about 40% of acoustic neuromas which have produced mild clinical symptoms are thought to stop growing spontaneously. Studies in Scandinavian countries where all deaths are followed by autopsies show that most ANs never reach the stage where clinical symptoms are apparent.
  2. All medical treatments, surgical or radiation, carry some risks. As the vast majority of ANs grow very slowly and are practically never cancerous, it makes sense to have a second MRI test at least 6 months after the first, to establish the growth rate. If the tumor is not growing, it might be possible to put off treatment forever.
  3. In time, safer treatments for acoustic neuromas, other than surgery or radiation, may be found.

Introductory comments about waiting and watching.

Waiting & watching is not procrastination. ANs are typically slow growing and non-cancerous, so the patient has plenty of time to do research in most cases. As the cure for ANs can be worse than the complaint, research is a good idea.

While waiting & watching during research makes perfect sense, once the decision for treatment has been made it is usually foolish to put it off any longer. Only when research shows that medical treatment might never be needed should waiting & watching become a permanent strategy.

  • The first thing to decide for wait & watchers is: "what will trigger my decision to seek treatment". One thing that should trigger it is the size of the tumor. It is generally thought that surgery on tumors larger than 2 cm carry more risks of hearing loss and facial paralysis. Tumors larger than 3 cm may no longer be suitable for radiation treatment. So if a tumor is close to these levels, and growing, medical treatment should be the preferred option.

  • Another thing that should trigger the decision is a change in symptoms. Most AN sufferers discover their tumor when they start losing hearing in one ear, or develop tinnitus (1), or start losing balance, or, in rare cases, start feeling numbness in the face. If any of these symptoms get noticeably worse, it can be a sign to stop waiting and seek treatment.

Two basic wait & watch options:

  1. Pre-treatment research

    Acoustic neuromas on average grow at rates close to 2 mm per year. They are never cancerous so they do not invade other tissues. However, treatment by physicians who are not experts in acoustic neuromas can lead to very undesirable consequences. Hence, a period of several months of watching & waiting to seriously research the various treatment options is recommended for almost all AN patients. A good plan is to wait for a second MRI test, about 6 months after the first, to establish the real growth rate. That is time enough to seriously research the options.

    Of course, there are a few exceptions to this rule.

    • In the past, patients sometimes waited until their tumor was large before consulting. Symptoms at diagnosis could be as severe as facial numbness or partial facial paralysis. This almost never happens now. With the advent of MRI imaging acoustic neuromas are usually diagnosed when they are still small and present few symptoms. However, there are still cases where the tumor is discovered late and may be threatening to do serious damage to surrounding nerves and brain structures. In such cases, waiting may be a bad choice. Consult with several doctors before you decide urgent treatment is required.
    • There are rare cases reported where the growth rate of the tumor is much higher than the average. Possible causes can include pregnancy or head trauma, such as a car accident. If rapid growth is suspected, obviously waiting is not a good option. Again, several doctors should be consulted to make sure that rapid growth is real.

  2. Decision not to seek medical treatment

    Some patients decide that the tumor may never need to be medically treated. This is called "conservative management". An MRI test is done at regular intervals (initially 6 months, then maybe every year or every 2 years). Any change in symptoms is closely monitored and considered as important as any change in size, if not more so. If the change is significant, the decision to stop waiting and seek treatment can be taken.

    Some studies show that about 40% of acoustic neuromas do not grow after diagnosis. A typical case is a patient over 60 years of age at the time of diagnosis, with rather mild symptoms and a small tumor. For instance, a recent Italian study shows that 8 selected patients over 65 with tumors extending less than 1cm into the CPA were followed for 5 years with conservative management only. "At the 5-year follow-up, no tumor growth was seen in six of the eight patients in the observation group. The other two patients exhibited a tumor growth rate of less than 2 mm per year, and their tumors still protruded less than 1 cm into the cerebellopontine angle. Therefore, neither of these patients required surgical intervention."


Although there may be many cases other than the elderly where the tumor will not grow, the danger of conservative management is wishful thinking. Acoustic neuroma surgery is no picnic, but treatment is preferable to letting the tumor grow and the symptoms worsen.

Very clear goals should be set to trigger an end to the wait & watch period. To avoid the natural tendency to put treatment off for too long, the patient should consult frequently with his doctors and not make the decision alone.

Waiting and watching carries the risk that hearing will be irretrievably lost. Generally speaking, none of the treatment options give much hope of improved hearing, so what is lost will probably stay lost. Another danger is the constant stress of knowing that there is an untreated tumor which might stay dormant for a while and then start growing again.

LINKS The Acoustic Neuroma Association (USA). There is a lot of useful information on this site and a guest book as well as a very active mailing list for patients. The Seattle (WA) Acoustic Neuroma Group - SANG. The AN Patient Archive site, full of information and patients' stories.

1 Tinnitus is a constant buzzing or ringing in the ear, often experienced by AN patients (and many non-AN patients for various reasons).