Schwannomatosis

People with schwannomatosis develop multiple schwannomas on cranial, spinal, and peripheral nerves. Like the other forms of NF, schwannomatosis varies greatly between patients. Roughly one third of schwannomatosis patients have segmental schwannomatosis, where tumor formation is limited to a single part of the body (ie. one limb or one section of the spine).

People with schwannomatosis have problems with chronic pain that often exceeds their neurological problems. The first symptom is most often pain, which can occur in any part of the body. Schwannomas develop on the outside of the nerve, but may push it aside or against another structure causing damage. Surgical management of schwannomatosis can be effective, when a tumor is completely removed, pain often subsides. When surgery is not feasible, management with a multi-disciplinary pain clinic is advised.

Do I have schwannomatosis?

As a newly recognized condition, data for developing diagnostic guidelines is limited. As such, the diagnostic criteria for schwannomatosis will be one the evolves as the condition becomes better understood. Presently, the diagnostic guidelines are as follows for definite schwannomatosis:

• Individual is over 30 years and all of the following,
• Has two or more non-intradermal schwannomas, at least one with histological confirmation
• No evidence of vestibular tumor on a high quality MRI scan
• Has no constitutional NF2 mutation

OR

• Has a pathologically confirmed non-vestibular schwannoma and a first-degree relative who meets the above criteria.

Possible additional diagnostic criteria for schwannomatosis includes:

• Individual is aged less than 30 years and all of the following,
• Has two or more non-intradermal schwannomas, at least one with histological confirmation
• No evidence of vestibular tumor on a high quality MRI scan
• Has no constitutional NF2 mutation

OR

• Individual is over age 45 years and all of the following,
• Has two or more non-intradermal schwannomas, at least one with histological confirmation
• No evidence of vestibular tumor on a high quality MRI scan
• Has no constitutional NF2 mutation

OR

• Has radiographic evidence of a non-vestibular schwannomas and first-degree relative meeting the criteria for definite schwannomatosis
• Diagnostic criteria for segmental schwannomatosis is the same, with the addition that schwannomas are limited to one limb or five or fewer contiguous segments of the spine.