The initial symptoms of melanoma include changes in existing moles or the development of unusual-looking growths or new pigmentation on the skin, according to Mayo Clinic. Moles that are not asymmetrical, have irregular borders, change color or have unevenly distributed colors may indicate melanoma. Moles that change over time or moles larger than 1/4 inch are also cause for concern.
Moles that have two different-looking halves, are not shaped regularly, or have scalloped, notched or irregular borders may indicate melanoma, reports Mayo Clinic. Moles that itch, bleed or otherwise evolve over time may also indicate a problem. Moles that have more than one color or with unevenly distributed color are also possibly symptomatic of melanoma. Any moles that change or evolve over time require evaluation by a medical professional.
Although many melanomas develop on parts of the body exposed to the sun, hidden melanomas also develop on areas such as the scalp, soles of the feet, palms of the hands, between the toes and on the genitals, notes Mayo Clinic. These hidden melanomas may also occur under the nails, in the urinary or digestive tracts, and in the mouth or the eye. A hidden melanoma in the eye may cause changes to vision.