What are the other Names for this Condition? (Also known as/Synonyms)

• Anorectal Mucosal Melanoma
• Melanoma, Non-Skin & Non-Ocular Location
• Mucosal Melanoma of Head & Neck

What is Mucosal Melanoma? (Definition/Background Information)

• A melanoma is a type of cancer that develops from cells, called melanocytes. Melanocytes are cells that produce melanin; the pigment that gives skin its color.
• Mucosal Melanomas develop from the mucous membrane lining the respiratory, gastrointestinal, or genitourinary tract.
• These melanoma types are rare and account for less than 5% of all melanoma cases; head and neck region alone accounting for half of these types.
• Other common sites of Mucosal Melanoma include:
  • Anorectal region (25%)
  • Female genital tract (20%)
  • Rarer sites include the urinary tract, gall bladder, and small intestine
• Mucosal Melanoma are diagnosed with the help of a biopsy and/or imaging studies, such as MRI of the affected areas, and are treated by surgical removal of the tumor
• Additionally, drugs may be needed depending on how advanced the disease is at the time of diagnosis

Mucosal Melanomas should not be confused with metastatic melanomas. A metastatic melanoma usually occurs from a melanoma of the skin or eye. Mucosal Melanomas of internal organs of the body, such as gallbladder, intestines, urinary bladder, etc. are considered primary melanomas meaning that they originate from the primary site.

In many cases, if Mucosal Melanomas are not diagnosed early, they can spread to other organs. When they spread from their site of origin to other locations, then they are called metastatic melanomas of Mucosal Melanomas origin.

Who gets Mucosal Melanoma? (Age and Sex Distribution)

• The peak incidence of Mucosal Melanoma of the head and neck region is in individuals aged 60-80 years
• A few research studies have reported a slight male predominance

What are the Risk Factors for Mucosal Melanoma? (Predisposing Factors)

• Concrete risk factors for Mucosal Melanomas or any predisposing exposure have not been established so far
• Tobacco smoke and other inhaled carcinogenic compounds (cancer-producing substances) have been implicated in the development of head and neck Mucosal Melanoma

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Mucosal Melanoma? (Etiology)

The exact cause of Mucosal Melanoma is presently unknown. Some of the possibilities being considered include:

• Some studies have shown that both chemical and physical stimulation, caused an increased production of melanocytes in the oral epithelium (lining of the inside of the mouth), resulting in pigmented (melanin colored) lesions
• Mucosal Melanomas most commonly involve gene changes in a protein, called KIT, which plays a key role in cell survival, proliferation, and differentiation

What are the Signs and Symptoms of Mucosal Melanoma?

Mucosal Melanomas may be present with non-specific symptoms like fatigue, loss of weight, loss of appetite, nausea, and other organ-specific symptoms. Depending on the site involved these symptoms vary and may include:

• Nose bleeds, breathing difficulty, facial pain, when the sino-nasal cavity (inside of the nose and sinuses) is involved
• Pigmented lesions/masses inside the mouth
• Pain or bleeding when the anorectal area (anus and the rectal portion of the alimentary tract, immediately before the anus) is involved
• Vaginal bleeding, discharge, pain or itching, with involvement of the female genital tract
• Pain or difficulty during swallowing, when the esophagus (food-pipe) is involved
• Blood in the urine during urethral involvement
• Abdominal pain or jaundice, if the gall bladder is affected

How is Mucosal Melanoma Diagnosed?

A thorough medical history and a complete physical exam by a physician are crucial for the diagnosis of Mucosal Melanoma. This is followed by certain tests which may include:

• Biopsy of lesions: The sampling of cells, to observe them under a microscope for signs of cancer
• Sentinel lymph node biopsy: The sentinel lymph node is a collection of immune cells that is closest to the cancer area (as determined by the physician)
• Imaging studies: MRI scan of the affected region is generally preferred

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Mucosal Melanoma?

Mucosal Melanomas are capable of spreading (metastasizing) to other areas as the disease progresses. Common sites involved in metastasis include:

• Lungs
• Liver
• Brain
• Lymph nodes
• Intestines

How is Mucosal Melanoma Treated?

Treatment options for Mucosal Melanoma include:

• Surgical excision of the tumor with sufficient negative margin (surrounding non-cancerous normal area is also removed). This is the treatment of choice
• Chemotherapy: Usage of drugs to kill cancer cells is an adjuvant therapy for more advanced diseases with cancer spread. Side effects depend on the drug used and may include nausea, vomiting, hair loss, diarrhea, fatigue, increased risk of infection, mouth sores, and easy bruising
• Immunotherapy, using agents that boost the immune system, such as interleukin-2 and interferon alpha are effective only in a small percentage of the patients. Side effects include flu-like symptoms, fever, head ache, muscle pain, etc.

How can Mucosal Melanoma be Prevented?

Presently, no clear predisposing factors have been established; besides, there is also no concrete information on how Mucosal Melanomas develop. Hence, the exact steps for prevention of these cancer types have not yet been determined.

What is the Prognosis of Mucosal Melanoma? (Outcomes/Resolutions)

• Considering the fact that Mucosal Melanomas are rare, not always readily visible, and present with highly variable non-specific symptoms; most cases of such cancers are quite advanced during the time of diagnosis, making the prognosis poor. Mucosal Melanomas in children tend to be less aggressive
• Mucosal Melanomas of the oral cavity are aggressive, and the outcomes are very poor; only half of those diagnosed live beyond 3 years (i.e., the estimated 3-year mortality rate is 50%)
• There is a high chance of cancer recurrence, even after treatment, especially within the first 3-years

Nevertheless, the prognosis depends upon a set of several factors, which include:

• Stage of tumor: With lower-stage tumors, when the melanoma is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage cancers, such as those with metastasis, the prognosis is poor
• Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
• Age of the individual: Older individuals generally have poorer prognosis than younger individuals
• The size of the melanoma: Individuals with small-sized melanomas fare better than those with large-sized ones
• Individuals with bulky disease have a poorer prognosis
• Involvement of vital organs may complicate the condition
• The surgical resectability of Mucosal Melanoma (meaning if the melanoma can be removed completely)
• Whether the cancer is occurring for the first time or is recurrent. Recurring cancers have worse prognosis compared to those that do not recur
• Response to treatment: Melanomas that respond well to treatment have better prognosis compared to melanomas that do not respond to treatment
• Progression of the condition makes the outcome worse (progressive Mucosal Melanoma)

An early diagnosis and prompt treatment of the condition generally yields better outcomes than a late diagnosis and delayed treatment.

Additional and Relevant Useful Information for Mucosal Melanoma:

Studies are on currently to develop targeted therapies that focus on the KIT gene mutation, commonly seen in Mucosal Melanoma. One such drug, called imatinib mesylate, blocks the activity of KIT and has proven to be effective in treatment.