Stage four melanoma refers to the advanced stage of skin cancer. In this condition, the disease spreads from the skin and affects other organs like the lungs.
Diagnosis for skin melanoma

The diagnosis for this kind of skin cancer includes the following tests:
1. Blood tests to determine the blood count and functioning of the liver
2. Ultrasound and imaging scans to determine the spread of cancer
3. A biopsy would be needed for examination
4. Various cancer specialists would conduct meetings to further understand the severity of the disease

Symptoms of stage four skin cancer

The first sign of skin cancer is a change in color of the skin or a mole. However, this sign is not universal for all the patients. Many cancer specialists first look at the primary tumor and observe whether it has spread to other organs as well. When skin cancer spreads to the lymph nodes, these may become matted or clumped. These lymph nodes appear hard when they are pressed by your doctor.

Size of the tumor
Typically, the size of the stage four melanoma is thicker; its size is approximately 4 millimeters. The size of the tumor may, however, vary from person to person. Research has revealed that the size of the tumor may shrink upon treatment but it may still metastasize.
Tumor ulceration

Stage four skin cancers may accompany skin ulceration as well. This means that portions of the skin may be broken. This rupture in the skin may begin from Stage 1 onwards. If you have a stage four melanoma, then the skin may or may not display ulcerations. Patients that have stage 4 melanoma along with having tumor ulcerations do not have high chances of survival, according to the American Cancer Society.

Self-examination
You can check yourself if you have skin cancer or not. The most obvious symptoms are;
• Change in the colour of the mole (s)
• When the shape of the mole is asymmetric
• When the colour of the mole changes its shape over a period
• Melanomas are usually the size of an eraser
• They also have uneven borders

Spreading of melanoma
In stage 3, the cancer spreads to lymph nodes or the skin around the primary tumor lymph nodes. In stage 4 melanoma, the tumor spreads to areas beyond the lymph nodes like the internal organs. In this stage, the melanoma may spread to the following organs;
• Liver
• brain
• bones
• Stomach or abdomen

The symptoms may vary depending upon the area where the cancer has spread. If the area where it has spread is the brain, then the patient may experience long-term headache. In case the area is the lungs then the symptoms may include cough and breathlessness. If you have been treated for stage 3 melanoma and are experiencing new pains, aches etc then you must consult a cancer specialist.

Treatment of this stage of cancer includes radiotherapy, chemotherapy, surgery, immunotherapy or targeted therapy.