SOX10

SOX10 is a protein that helps control how certain types of cells grow, develop, and function in the body. It plays a particularly important role in the development of cells in the nervous system and melanocytes, which are pigment-producing cells found in the skin. Pathologists use SOX10 as a marker to identify tumours that arise from these cells. Testing for SOX10 helps diagnose tumours of nerve sheath, melanocytic, and myoepithelial origin.

What types of normal cells and tissues express SOX10?

SOX10 is normally found in the nucleus of cells involved in the development and maintenance of specific tissues.

These include:

• Schwann cells – Cells that wrap around and protect nerve fibers.

• Melanocytes – Pigment-producing cells found in the skin, hair, and eyes.

• Myoepithelial cells – Support cells found in glands such as the breast, salivary glands, and sweat glands.

In these normal cells, SOX10 helps regulate gene activity that controls growth, repair, and function.

How do pathologists test for SOX10?

Pathologists test for SOX10 using a laboratory method called immunohistochemistry (IHC). A small tissue sample is treated with special antibodies that bind to the SOX10 protein. If SOX10 is present, the test produces a visible colour change in the nucleus of the cell, which can be seen under the microscope. A positive result means the cells contain SOX10, while a negative result means they do not.

SOX10 testing is used to help determine the type of tumour, especially when the tumour is made up of nerve cells, melanocytes, or myoepithelial cells. It is particularly helpful when other tests are inconclusive.

What types of tumours express SOX10?

SOX10 is commonly found in both benign (non-cancerous) and malignant (cancerous) tumours that come from Schwann cells, melanocytes, or myoepithelial cells.

Benign tumours

• Schwannoma – A non-cancerous tumour of Schwann cells, usually found along nerves.

• Melanocytic nevi (moles) – Common benign skin growths made up of melanocytes.

• Pleomorphic adenoma – A benign tumour of the salivary gland that may contain myoepithelial cells.

Malignant tumours

• Malignant peripheral nerve sheath tumour (MPNST) – A rare cancer that develops from the protective cells around nerves.

• Melanoma – A serious form of skin cancer that arises from melanocytes. SOX10 is often used to confirm the diagnosis.

• Acinic cell carcinoma – A cancer of the salivary glands that can express SOX10 in some cases.

• Myoepithelial carcinoma – A rare cancer that arises from myoepithelial cells in glands or skin.

• Epithelial-myoepithelial carcinoma – A tumour with both epithelial and myoepithelial components, most often found in salivary glands.

Because SOX10 is expressed in these tumour types, it helps pathologists make a more accurate diagnosis, especially when other features are unclear.

Why is SOX10 important in a pathology report?

SOX10 is important because it helps pathologists identify the type of cells that make up a tumour. This is especially helpful when:

• The tumour may have come from nerve, skin, or glandular tissue.

• The diagnosis is uncertain and other markers are inconclusive.

• Distinguishing melanoma from other skin cancers.

• Identifying tumours involving nerve sheaths or salivary glands.

Knowing whether a tumour expresses SOX10 helps doctors determine the tumour’s origin and choose the most appropriate treatment.

Questions to ask your doctor

• What does the SOX10 result in my pathology report mean?

• Does the presence of SOX10 help confirm the type of tumour I have?

• Were other markers tested along with SOX10?

• How does SOX10 affect my diagnosis or treatment plan?

• Are additional tests needed to better understand my tumour?