|
Typically people think of skin cancer when they hear the word melanoma. This is quite often the case with this form of cancer, but melanoma can also occur in the least expected parts of the body.
Melanoma can be found in the eyes, rectum, vagina, intestines, mouth and gums, palms and soles of the feet, covering of brain and spinal cord as well as underneath the fingernails and toenails. The melanocytes in the skin which give rise to melanoma are also located in the eyes and produce melanin pigments to protect nearby cells from the damaging effects of sun exposure. In other areas of the body, the melanocytes do not serve that same function since those areas are not exposed to the skin. The reasons these areas develop melanoma are still unknown, since the most common reason for the cancer is overexposure to the sun. A damaged gene, known as the p16 gene, can also be a factor leading to melanoma. People who are not born with this genetic mutation, can have an acquired mutation which occurs from ultraviolet-induced damage.
Melanoma of the eye is referred to as ocular melanoma. Sun is a factor in the development of this cancer that usually occurs in the back of the eye. Especially people with atypical mole syndrome, need yearly eye examinations to be sure melanoma has not developed. Diagnosing this cancer is difficult since the areas are not readily seen when a tumor develops and a biopsy cannot be performed so easily as it can on melanoma of the skin.
Melanoma which occurs in the membranes covering the brain and spinal cord is called leptomeninges. This is one of the rarest places for melanoma to develop and usually occurs in someone with a large congenital nevus -- a large mole existing since birth.
Melanoma of the palms and soles is a difficult one to find since we rarely look at the soles of our feet. Once these cancers are found they have usually invaded the skin layers deeply and spread to other internal organs.
Under the fingernails and toenails melanoma is called subungual melanoma. These cancers often come after a long period of chronic nail infections. The only treatment for this is amputation of the toe or finger.
Melanoma of the mouth or gums is also very rare and happens most frequently in Asians. Prognosis for this cancer is fairly unfavorable.
In the anus, rectum and vagina, melanoma is rare and occurs randomly. The symptoms early on are similar to hemorrhoids, but don’t go away. These areas are difficult to observe for changes and thus, are detected late and have a disappointing prognosis.
Another melanoma that is not typical, is amelanotic melanoma. This kind lacks the pigmentation and color that melanoma typically has. This type of mole is less likely to be noticed because it appears more normal, yet the prognosis can be just as grim if it isn’t caught early like the other melanomas.
Melanoma can also develop in the body without knowing what the primary site of the cancer was. Perhaps, a mole was scraped off or fell off on its own. This can be the origin for the melanoma and treatment becomes more difficult because the size of the mole was not determined through biopsy.
Some people will also have more than one primary melanoma. This situation reduces survival rates and involves more aggressive treatment. Just having one melanoma occur increases the odds of having another appear at another time in life. When these new primaries develop they are usually in another area of the body than where the first primary was found.
Children rarely get melanoma, but the risk still exists. Most moles do not develop until a child goes through puberty but some children do get moles starting at the age of five. These youngsters likely have atypical mole syndrome and need careful observation of their moles as well as guidance in skin protection during sun exposure. Some kids will also get melanoma from an existing congenital nevus, especially one that is very large and hairy. Also, children can get melanoma in the eye just as adults do.
Pregnant women also appear to be at a higher risk of developing melanoma due to the increase in the production of melanin, as can be seen on some women who develop a dark line down their bellies during pregnancy. Melanoma may occur during or shortly after pregnancy, and research concludes that pregnancy can contribute to melanoma and that waiting a time period after diagnosis before getting pregnant again is advised.
Checking obvious moles is the first line of defense against melanoma and if you have a higher than usual risk for the cancer, checking those hard-to-observe areas is recommended as well. Any changes or suspicious lesions should be checked out immediately by a skilled practitioner.
| 
