September 2, 2015
font size

Melanoma (cont.)

Medical Author:
Medical Editor:

What are the causes and risk factors for melanoma?

Guideline # 5: Individual sunburns do raise one's risk of melanoma. However, slow daily sun exposure, even without burning, may also substantially raise someone's risk of skin cancer.

Factors that raise one's risk for melanoma include the following:

  • Caucasian (white) ancestry
  • Fair skin, light hair, and light-colored eyes
  • A history of intense, intermittent sun exposure, especially in childhood
  • Many (more than 100) moles
  • Large, irregular, or "funny looking" moles
  • Close blood relatives -- parents, siblings, and children -- with melanoma

The presence of close (first-degree) family with melanoma is a high risk factor, although looking at all cases of melanoma, only 10% of cases run in families.

Having a history of other sun-induced skin cancers, such as the much more common basal cell or squamous cell carcinomas, indirectly raises one's risk because they are markers of long-term sun exposure. The basic cell type is different, however, and a basal cell or squamous cell carcinoma cannot "turn into melanoma" or vice versa.

How can people estimate their level of risk for melanoma?

The best way to know one's risk level is to have a dermatologist perform a full body examination. That way one will find out whether the spots one has are moles and, if so, whether they are funny looking in the medical sense.

The medical term for such moles is atypical. This is a somewhat confusing term, because among other things the criteria for defining it are not clear, and it's not certain that an atypical mole is necessarily precancerous. Patients who have lots of "atypical moles" (more than 24) do have a higher risk for developing melanoma but not necessarily within one of their existing funny-looking moles. It may be a challenge to find the "baby melanoma" in the middle of a back full of large, dark, or irregular moles. If someone has such moles, a doctor will recommend regular surveillance and may recommend biopsy of the most unusual or worrisome looking moles.

Sometimes, one learns at a routine skin evaluation that one does not necessarily need annual routine checkups. In other situations, a doctor may recommend regular checks at six-month or yearly intervals.

What are the types of melanoma?

The main types of melanoma are as follows:

  1. Superficial spreading melanoma: This type accounts for about 70% of all cases of melanoma. The most common locations are the legs of women and the backs of men, and they occur most commonly between the ages of 30-50. (Note: Melanomas can occur in other locations and at other ages, as well.) These melanomas are flat or barely raised and have a variety of colors. Such melanomas evolve over one to five years and can be readily caught at an early stage if they are detected and removed. An "in situ" melanoma refers to a very thin superficial spreading melanoma that does not extend beyond the junction of the dermis and epidermis, the normal location for melanocytes.
  2. Nodular melanoma: About 20% of melanomas begin as deeper, blue-black to purplish lumps. They may evolve faster and may also be more likely to spread. Untreated superficial spreading melanomas may become nodular and invasive.
  3. Lentigo maligna: Unlike other forms of melanoma, lentigo maligna tends to occur on places like the face, which are exposed to the sun constantly rather than intermittently. Lentigo maligna looks like a large, irregularly shaped or colored freckle and develops slowly. It may take many years to evolve into a more dangerous melanoma or may never become a more invasive form. Because of the unpredictability of future behavior, removal is recommended.

There are also other rarer forms of melanoma that may occur, for example, under the nails (subungual), on the palms and soles (acral lentiginous), uveal or choroidal (ocular), oral or vulvar mucosa, or sometimes even inside the body.

Medically Reviewed by a Doctor on 4/16/2015

Source: MedicineNet.com
http://www.medicinenet.com/melanoma/article.htm

Cancer

Get the latest treatment options.

Melanoma Related Articles
advertisement
advertisement
Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations