Melanoma is generally described as a form of cancer that develops in melanocytes. Melanocytes are on the other hand described as the cells which give pigment to skin, eyes and hair. You would therefore expect the cancer to only develop on body parts such as the outer skin, hands and feet. This is not the case. As it happens, melanocytes also occur in mucous membranes.
Mucous membranes are found on outside of body cavities and as linings of canals that connect internal organs to the outside. A good example is nasal passages which connect the respiratory system to nostrils. Other places you will find the mucous membrane include the vagina, urethra, gut and anus. Melanocytes occur in the basal epithelial cell layer. When malignancy starts in these cells, it is known as mucosal melanoma.
What is mucosal melanoma (MM)?
First of all, what is melanoma? Melanoma and basically cancer develops when cells divide very fast and fail to die naturally. This results in accumulation of functionless cells which collect to form a lump.
Only about 1.2 of all melanomas is accounted for by malignancy in the mucous membranes. The problem is that tumors are usually detected later in their developmental stages due to their location. Advanced melanomas are highly malignant. This leads us to another question, what is malignant melanoma?
The main reason as to why cancer is among top killing diseases is because its cells often migrate, invading other organs and tissues in the process. Once it has spread, treatment may be necessary for infinite number of tumors, most of which can show up anywhere. Malignancy is used to describe this behavior. It is estimated that about 50% of all melanomas are malignant, MM being an example.
MM can develop in the following areas;
- Genitals (vulva, vagina)
- Respiratory tract
- Urinary tract
The disease can develop in anyone but tends to occur more in people over 70 years of age.
Mucosal melanoma symptoms
Mucosal melanoma symptoms and signs are dependent on the affected part. It is very common for patients to misdiagnose the disease.
Neck and head areas
- Obstruction of nasal cavity
- Nose bleeding
- Blood in mucus
- Discolored spot or patch in mouth
- Not being able to smell
- Dentures falling out of place
- Presence of a bump that may bleed but not cause pain
Most melanomas on anus develop on the region where the soft lining borders normal skin. They may be accompanied by;
- Blood, which may be present in stool
- Pain in the rectum or anus
- Presence of a lump that doesn’t go away
Melanoma in genitals is more common in women. It can develop on vagina or vulva. Mucosal melanoma warning signs in genitals may include;
- Discolored area on vulva
- Vaginal discharge
- Feeling pain when having sex or after
- A lump that doesn’t go away
It is very important that you check with your doctor if such symptoms are to occur. While this cancer is quite rare, it is one of the most aggressive ones. Misdiagnosis and late detection have also been a problem in amelanotic melanoma cytology.
Mucosal melanoma causes
It is largely agreed that melanoma on face for example may have a lot to do with direct sun and devices such as tanning beds. The common thing about the sun and such devices is that they emit UV rays. These rays are known to cause damage to DNA which then leads to mutation. The same cannot be said of mucosal melanoma. In fact, there currently is no strong evidence linking the disease with a main cause or risk factor. Some reports suggest that it has something to do with genetic mutation. Potential risk factors include;
In oral regions;
- Products with ability to cause mutations. They can be present in air or food products
- Dentures which are out of position or have not been fitted properly
In anal cavity
- Infections caused by viruses
- Random mutations that run in the family
- A condition that causes chronic inflammation. It may be caused by diseases such as lupus, arthritis and inflammatory bowel disease.
- Presence of materials or products that cause irritation. This may include soaps, rings and clothing.
There is no guarantee that any of these factors will lead to mucosal melanoma. They only increase the risk of developing the disease.
Mucosal melanoma prognosis and staging
As mentioned earlier, this disease is rare. For vaginal, vulvar and anal melanoma, a three-stage system is used.
- Stage 1 – tumors are only present in a local organ or part of the mucous membrane. This means that such tumors can easily be cut out if their location allows.
- Stage 2 – here, malignancy has entered the lymphatic system. Local lymph nodes have been invaded and are likely swollen or will soon swell. Lymph nodes in the groin area are first to be invaded.
- Stage 3 – stage 3 melanoma malignant cells have reached distant organs, mostly through the circulatory system.
For mucosal melanoma in neck and head areas, the AJCC-TNM staging system is used. Basically, the system focuses on describing the status of the tumors. The first stage (T3) describes a mucosal disease. Stage 2 (T4A) describes tumors that have reached the soft layers of epithelial tissue. They may also have developed into cartilages where involved. Larger tumors in this stage have reached immediate skin layers. The final stage (T4B), describes tumors that have reached vital sections or organs such as skull, brain or cranial nerves.
Prognosis is best before tumors have left local positions. But as said earlier, mucosal melanoma is often caught in its later stages. 5 year survival rate is therefore low. Anal and rectal melanoma has a survival rate of about 20%. This is about 5% lower than when it occurs in the vagina. On head and neck survival rate for the next 5 years is about 25%. The vulva comprises of some more external organs such as labia majora. A melanoma on such areas is easier to notice. For this reason, survival rate is a bit higher, between 25% and 70%. And how fast does melanoma grow? It mostly depends on its type and stage. The constant fact is that it grows even faster after metastasis.
You may find it helpful comparing types of melanoma to understand this disease fully. You can start with acral lentiginous melanoma pictures and ocular melanoma since they are also considered rare.
Mucosal melanoma diagnosis
This test is very popular for melanomas that develop on the skin or even when identifying subungual melanoma symptoms. It is however not very applicable for some mucosal melanomas. Physical examination involves looking for signs of irregularities in moles or skin growths.
Biopsy is the most accurate way to tell if some symptoms are indicating a mucosal melanoma or not. Here, a small tissue will be extracted and tested in the lab. Most doctors prefer excisional biopsy for it is more accurate.
Depending on the results of the biopsy, imaging tests may also be taken. CT scans and MRIs are good examples. They produce pictures and images which show how thick a tumor is, how much it has spread and its location.
Mucosal melanoma treatment
Surgery is the primary mucosal melanoma treatment option. It works very effectively for a small melanoma. The tumor will first be located. Imaging tests will then be done to show the size and location of the tumor. A doctor will then draw excisional margins. Finally, an excision will be made and the tumor cut out. When tumors have developed on delicate areas especially on head and neck areas, surgery may not be an option.
Chemotherapy is a main alternative especially when surgery is not an option. Here, drugs will be injected directly or be administered systematically. The drugs will work by killing cells that rapidly divide. As you may already know, cancer cells divide very fast.
Other than chemo, radiotherapy is also a main alternative where tumors cannot be removed surgically. The treatment uses X-rays which have been focused on a tumor to kill malignant cells. Radiotherapy is often used to stop spreading of malignant cells as well as a follow-up treatment after surgery.
Drugs used for immunotherapy work by boosting the immune system. As a result, the body is able to recognize and destroy cancer cells before they can form tumors. Not everyone is eligible to this treatment. This is because drugs used come with a range of side effects that may be of much harm to some people.
When patients take chemotherapy drugs, the drugs end up killing even healthy cells that divide fast. Targeted therapy addresses this issue. Here, drugs that specifically target cancer cells are used. The treatment is one of the most recent ones.
Other treatment options are being developed as research goes on. For example, there are hopes that vaccines will be available sometimes in the future. Other than technical treatments, patients should also consider going for psychotherapy. This can even take the form of sharing and listening to stories from mucosal melanoma survivors. Cancer is one of the most distressing diseases. Without support and encouragement, it can end up killing you through demoralization.
It is hard to prevent something you don’t really know its causes. Regardless, avoiding the risk factors indicated earlier in this article may help. The best prevention approach however is to maintain routine checkups and seeking medical attention for any condition whose origin you fully can’t explain.