The most important warning sign for melanoma is any change in size, shape, or color of a mole or other skin growth, such as a birthmark. Watch for changes that occur over a period of weeks to a month. The ABCDE system tells you what changes to look for. 1  A is for asymmetry.
http://www.webmd.com/melanoma-skin-cancer/tc/skin-cancer-melanoma-symptoms
1 The brain looks familiar. 2  Melanocytes arise from the same part of the early embryo as the brain, so the brain might be a very natural environment for melanoma tumors to grow in. 3  Often, by the time the patient first exhibits symptoms, they already have multiple lesions. 4  Brain metastases tend to be very aggressive.
https://www.aimatmelanoma.org/stages-of-melanoma/brain-metastases/
More than 60% of all Stage IV melanoma patients will develop brain metastases at some point but certain factors can increase that risk: 1,2. 1  The primary tumor was on the head, neck, trunk, or abdomen. 2  The primary tumor was ulcerated or deep or invasive. 3  The melanoma was unresectable Stage III or Stage IV when diagnosed.
https://www.aimatmelanoma.org/stages-of-melanoma/brain-metastases/
Melanoma. Melanomas can develop anywhere on your body. They most often develop in areas that have had exposure to the sun, such as your back, legs, arms and face. Melanomas can also occur in areas that don't receive much sun exposure, such as the soles of your feet, palms of your hands and fingernail beds. These hidden melanomas are more common in people with darker skin. The first melanoma signs and symptoms often are: 1  A change in an existing mole.
http://www.mayoclinic.org/diseases-conditions/melanoma/basics/symptoms/CON-20026009
You may not have any symptoms in the early stages of melanoma. Or a melanoma may be sore, or it may itch or bleed. Most melanomas start as a new skin growth on unmarked skin. The growth may change color, shape, or size. These types of changes are an early sign that the growth is melanoma. But melanoma can also develop in an existing mole or other mark on the skin.
http://www.webmd.com/melanoma-skin-cancer/tc/skin-cancer-melanoma-symptoms
Melanoma can also form in your eyes and, rarely, in internal organs, such as your intestines. The exact cause of all melanomas isn't clear, but exposure to ultraviolet (UV) radiation from sunlight or tanning lamps and beds increases your risk of developing melanoma.
http://www.mayoclinic.org/diseases-conditions/melanoma/basics/definition/con-20026009
The term 'metastatic melanoma', also known as Stage IV melanoma, is used when melanoma cells of any kind (cutaneous, mucosal or ocular) have spread through the lymph nodes to distant sites in the body and/or to the body's organs. The liver, lungs, bones and brain are most often affected by these metastases. As with other cancers, metastases occur when the melanoma is not caught in the early stages. Oftentimes, symptoms only become present once it is has already spread. Once melanoma has spread, determining the original type is nearly impossible – which makes planning the right treatment extremely difficult. Early detection is crucial.
https://www.melanoma.org/understand-melanoma/what-is-melanoma/metastatic-melanoma
The risk of melanoma seems to be increasing in people under 40, especially women. Knowing the warning signs of skin cancer can help ensure that cancerous changes are detected and treated before the cancer has spread.
http://www.mayoclinic.org/diseases-conditions/melanoma/basics/definition/con-20026009
Brain Metastases. Brain metastases, a specific form of Stage IV melanoma, are one of the most common and difficult-to-treat complications of melanoma. They differ from all other metastases in terms of risk factors, diagnosis, and treatment.
https://www.aimatmelanoma.org/stages-of-melanoma/brain-metastases/
When melanoma occurs in people with darker skin, it's more likely to occur in a hidden area. Hidden melanomas include: 1  Melanoma under a nail. 2  Acral-lentiginous melanoma is a rare form of melanoma that can occur under a fingernail or toenail. 3  It can also be found on the palms of the hands or the soles of the feet.
http://www.mayoclinic.org/diseases-conditions/melanoma/basics/symptoms/CON-20026009
melanoma metastasis symptoms
A change in an existing mole is the symptom of metastasis melanoma.