Mucosal melanoma is a rare form of melanoma, making up only about 1% of melanoma cases. As with other areas of the skin, melanocytes, the pigment producing cells of the body, are also present in the mucosal surfaces of the body, lining the sinuses, nasal passages, oral cavity, vagina, anus and other areas. Just like melanocytes in other parts of the body, these can transform into cancerous cells, resulting in mucosal melanoma.
Approximately 50% of mucosal melanomas begin in the head and neck region, 25% begin in the ano-rectal region and 20% begin in the female genital tract. The remaining 5% include the esophagus, gallbladder, bowel, conjunctiva and urethra.
Unlike most cases of melanoma of the skin, mucosal melanoma is not considered to be related to or affected by UV exposure. Additionally, there are no obvious identified risk factors, not even family history. Lacking an identifiable culprit and given its rare occurrence, most cases of mucosal melanoma are quite advanced once identified.
A 2012 comprehensive review of primary mucosal melanomas in the International Journal of Clinical and Experimental Pathology provides a helpful overview of mucosal melanoma epidemiology and diagnosis.
Mucosal melanoma can be a very lonely diagnosis. Be sure to visit MPIP, the MRF's online forum, to meet other mucosal melanoma patients.
Signs & Symptoms of Mucosal Melanoma
Mucosal melanoma symptoms vary greatly. It is important to let your doctor know if you spot anything suspicous in your mouth or nasal passages, including unexplained sores or sores that won't heal. Unexplained bleeding from the rectum or vagina, hemorrhoids that won't heal or seem to worsen and pain during a bowel movement may also be signs of mucosal melanoma.
Diagnosing Mucosal Melanoma
Mucosal melanoma often goes misdiagnosed, primarily because of the anatomical location of the disease and becasue of the lack of discernible signs and symptoms. For instance, melanoma of the ano-rectal region is often misdiagnosed as hemorrhoids.
Genetic Mutations in Mucosal Melanoma
Melanoma is typically classified by clinical characteristics, such as depth, ulceration and site of origin. However, in the past several years, mutations in certain proteins are allowing scientists to further define the melanoma at the molecular level. The most common mutation in mucosal melanoma is found in a protein called KIT. The changes in the KIT protein play an important role in tumor growth and the development of possible treatment options. The BRAF mutation, found in about half of all cutaneous melanoma cases, is rarely found in mucosal melanoma.
Mucosal Melanoma Treatment
Treatment for mucosal melanoma is not always entirely clear. Treatment will depend on the size, type and location of the tumor. Do your best to find a treatment team who has experience treating mucosal melanoma.
It is important to learn about all possible treatment options, discuss them with your treatment team and decide on what is best for you. Surgery is a common treatment option for a primary mucosal melanoma tumor. Additional options may include FDA approved immunotherapies and some clinical trials, which may include combinations of approved and not-yet approved therapies . Some mucosal melanoma patients who have tumors with KIT mutations have had success using imatinib (Gleevec). Imatinib is not FDA approved for the treatment of metastatic melanoma but is avaialble in some clinical trials.
The MRF would like to recognize and thank The Susan Fazio Foundation for Melanoma Research. This foundation continues to raise funds dedicated to the research of mucosal melanoma. Please visit their website to learn more about their efforts in mucosal melanoma.