The diagnosis of schwannomatosis is made on the basis of clinical findings.

Individuals are considered to have definite schwannomatosis if they meet the following criteria:

1) Two or more schwannomas (with at least one that has been shown to be a schwannoma on a pathology report).

AND

2) Lack of radiographic evidence of vestibular nerve tumor on an imaging study performed after age 18 years.

Individuals are considered to have probable schwannomatosis if they meet the following criteria:

1) Two or more schwannomas (with at least one that has been shown to be a schwannoma on a pathology report) without symptoms of eighth nerve dysfunction at age >30 years

OR

2)    Two or more schwannomas (with at least one that has been shown to be a schwannoma on a pathology report) in an anatomically limited distribution without symptoms of eighth nerve dysfunction at any age.

Some people may have a segmental form of schwannomatosis, meaning that symptoms are limited to only one part of the body. It is important to distinguish between segmental schwannomatosis and NF2, as the symptoms of both can overlap.