Schwannoma - Symptoms & Causes

Q: What is schwannoma?

Schwannoma, also known as neurilemmoma , is a typically benign tumour that originates from the Schwann cells, which form the sheath around peripheral nerves. These tumours can develop anywhere in the body but are most commonly found in the head, neck, and extremities, including within the inner ear canal, where they are known as acoustic neuromas. How rare or common is it? Schwannomas are relatively uncommon. Worldwide, these tumours represent about 5% of all soft tissue tumours. In Singapore, the exact incidence is not well-documented but follows global rarity trends.

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What is schwannoma?

Schwannoma, also known as neurilemmoma, is a typically benign tumour that originates from the Schwann cells, which form the sheath around peripheral nerves.

These tumours can develop anywhere in the body but are most commonly found in the head, neck, and extremities, including within the inner ear canal, where they are known as acoustic neuromas.

How rare or common is it?

Schwannomas are relatively uncommon. Worldwide, these tumours represent about 5% of all soft tissue tumours. In Singapore, the exact incidence is not well-documented but follows global rarity trends.

What are the symptoms of schwannoma?

The symptoms of schwannoma depend on the tumour's location and size. Common symptoms include:

Pain or numbness in the affected area due to nerve compression
Weakness or loss of muscle function, if the tumour affects motor nerves
In cases of acoustic neuromas, symptoms might include hearing loss, tinnitus (ringing in the ears), and balance difficulties

What causes schwannoma?

The precise cause of schwannomas is not fully understood. However, some cases are associated with genetic disorders such as neurofibromatosis type 2 (NF2), which involves a mutation in the NF2 gene on chromosome 22. This mutation leads to the loss of function of merlin, a tumour suppressor protein, resulting in tumour formation.

While schwannomas are usually benign and slow-growing, they can cause significant complications as they enlarge, including:

Severe nerve damage leading to neurological deficits.
Discomfort and dysfunction of nearby organs or structures.
Rarely, malignant transformation into a more aggressive form known as malignant peripheral nerve sheath tumour.

How do you prevent schwannoma?

Currently, there are no known measures to prevent schwannomas, particularly because the specific causes are not completely understood. In individuals with neurofibromatosis, regular monitoring and early intervention can help manage the condition and prevent complications.