Melanoma is a type of cancer, most often of the skin. However, melanoma can also occur in the tissue that lines internal areas of the body called mucous membranes and is known as mucosal melanoma. Mucosal melanoma (MM) is a rare form of cancer that affects the pigment-producing cells of the mucous membranes, known as melanocytes.
Mucosal melanoma accounts for only about 1% of all cases of melanoma in Australia.
*Image courtesy of Melanoma Institute Australia
Where does mucosal melanoma occur?
Mucosal melanoma starts in the mucous membrane lining of different areas of the body. Approximately 50% of mucosal melanomas begin in the head and neck region (such as the sinuses, nasal cavity, oral cavity, throat), 25% begin in the ano-rectal region and 20% begin in the female genital tract (such as vulva and vagina). The remaining 5% include the oesophagus, gallbladder, bowel, and urethra.
What are the causes and risk factors of mucosal melanoma?
The underlying cause of mucosal melanoma is unclear. Possible risk factors have been identified and depend on the location of the cancer. These risk factors may include:
Although research has found an association with these factors, MM can occur in any person, at any age, any gender and without exposure to possible risk factors.
What are the signs and symptoms of mucosal melanoma?
Mucosal melanomas can be difficult to diagnose because the tumour is hidden inside your body. Some mucosal melanomas may appear as areas of irregular pigmentation, while others will not.
The signs and symptoms vary depending on the location of the cancer.
Head and neck:
Vulva or vagina:
Anus:
How is mucosal melanoma diagnosed?
If your doctor thinks you may have a mucosal melanoma, you will most likely undergo a biopsy of the suspect tissue. A small sample of cells will be removed from the affected area and examined under a microscope. If the result of the biopsy indicates mucosal melanoma, you may have further tests to find out more about the melanoma and if it has spread to your lymph nodes or other areas of your body. This may include imaging such as a CT scan, MRI, PET scan or an ultrasound of the regional lymph nodes.
Information describing the terminology used in melanoma diagnosis can be found here.
Genetic testing– Genetic testing on a sample of cancerous tissue from the mucosal melanoma or site of spread, looks for certain genetic mutations that are thought to be involved in the growth of mucosal melanoma. Knowing your ‘mutation status’ may help to inform future treatment options. The common genetic mutations are:
Staging of mucosal melanoma
Staging refers to how limited or advanced the melanoma is at the time of diagnosis. The higher the stage, the further the melanoma has spread in your body. The stage you are diagnosed with will guide your treatment team to develop your treatment plan.
There have been several staging categorisation systems of mucosal melanoma. Staging in mucosal melanoma can be very complex and depends on may factors, including the type of MM you have. If you’re interested in learning more about staging and how it might apply to your MM, ask your doctor to explain it to you in a way you understand.
Note: The medical team will use the information about the stage of mucosal melanoma to determine the best possible treatment. It is important to be aware that every patient is treated individually and not all patients with the same stage of melanoma at diagnosis will be treated the same way. There are other factors (such as the presence of genetic mutations, other health conditions) which will result in some patients with the same stage of melanoma being treated differently.
How is mucosal melanoma treated?
It is important to see a doctor who specialises in treating patients with your specific type of melanoma. Your GP can refer you to a center that treats MM. It is important to note that you may need to travel for treatment, depending on where you live (speak with your GP, the treatment center, the cancer council or the MPA telehealth nurse service to discuss possible travel and accommodation assistance).
Treatments for mucosal melanoma depend on its location in the body and whether it has spread (metastasised) to other parts of your body. Treatment options may include surgery, radiotherapy, systemic therapy, or a combination.
Surgery- Surgery is often the first treatment choice for a mucosal melanoma. A surgeon will aim to remove the melanoma with a clear margin (area of normal tissue surrounding the melanoma), but this may not always be possible. Sometimes, nearby lymph nodes are investigated or removed as part of the surgical treatment called a sentinel lymph node biopsy (procedure that identifies, removes and examines the closest lymph nodes to the melanoma that may contain melanoma cells). If the melanoma is small and hasn’t spread, surgery may be the only treatment required.
Radiotherapy- Radiotherapy uses targeted x-rays to destroy cancer cells. You may have radiotherapy after surgery for mucosal melanoma, especially if the cancer cells have spread or complete removal of the melanoma has not been able to be achieved with surgery.
You may have radiotherapy alone if the mucosal melanoma is in a place that is difficult to reach with surgery or surgery will be particularly disfiguring.
Systemic treatments- Systemic treatments are those that target the entire body, circulating through the bloodstream to kill cancer cells. Systemic treatment may be offered if your MM has spread to lymph nodes or organs. Systemic treatments may be used after surgery (called adjuvant therapy), or when mucosal melanoma has spread or cannot be surgically removed. Systemic treatment can include:
Clinical trials- Despite advances in the understanding of mucosal melanoma, it can be difficult to treat. Research is underway to identify new treatment approaches for mucosal melanoma. Clinical trials are used to test new treatments to see if they are better than the currently available treatments. They are vital for improving outcomes for people with cancer. Your doctor may suggest that you take part in a clinical trial as your treatment for mucosal melanoma. You can read more about clinical trials at www.australiancancertrials.gov.au.
Note: It is important to work closely with a team of medical professionals to develop a personalized treatment plan that considers your individual needs and circumstances.
Questions to ask your doctor
< How did I get mucosal melanoma?
< Do I need a biopsy? What will that consist of? When will I know the results?
< Is this related to cutaneous (skin) melanoma? Should you check the rest of my skin?
< Has the melanoma spread?
< What are the stages of mucosal melanoma? What is my stage?
< If I need more tests, what will they be?
< Should I get a second opinion or explore another treatment centre with more experience with mucosal melanoma?
< How will this diagnosis affect my quality of life?
< What is my prognosis?
< Have you tested my melanoma for genetic mutations?
< What are my treatment options?
< Am I eligible for a clinical trial?
< What will be our “Plan B” if “Plan A” doesn’t work?
< What are the side effects of the treatment you recommend?
< Will I be able to continue my normal daily life?
< What type of follow-up will I need?
What supports are available?
Having a rare melanoma can feel isolating. Additionally, treatment can be disfiguring or impact your quality of life in many ways. Here are some support options available:
Melanoma Patients Australia (MPA)-
Rare Cancers Australia- offer support and advocacy for rare cancers. www.rarecancers.org.au
Melanoma Institute of Australia (MIA)- offer information sheets on mucosal melanoma
Mucosal-Melanoma-Brochure-2022.pdf
International websites
Melanoma Research Foundation – www.melanoma.org
AIM at Melanoma Foundation- www.aimatmelanoma.org
Mucosal Melanoma Warriors- www.mmwarriors.org
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We recognise, value and celebrate diversity and act in the spirit of inclusion.
