Malignant melanoma is the most serious form of skin cancer. Malignant melanoma occurs in the skin's pigment-producing cells, the melanocytes. When exposed to UV light, the production of pigments is stimulated and we become tanned. This makes the skin better able to withstand exposure to the sun's rays. If the genome of a melanocyte is damaged due to UV radiation, the melanocyte may gradually change and begin to divide uninhibitedly to form a malignant melanoma. This can take time, as from the onset of an injury in the genome of a melanocyte, it can be decades until a malignant melanoma develops.
Malignant melanoma in the skin is most often detected when the patient themselves, or someone in their surroundings, notices a new or altered mole. About half of all skin melomas occur in previously healthy skin and half in existing 'liver spots' or 'moles' (these are the same thing). The diagnosis of malignant melanoma is made by removing the suspected skin change and then analysing under a microscope. Malignant melanomas should be removed with the margin (healthy tissue) around them and surgery is usually a curative measure.
Malignant melanoma is the fastest growing form of cancer. Every year, more than 4 000 Swedes are affected by malignant melanoma and 500 die from the disease, which is more than in traffic. Read more about malignant melanoma at the Swedish Cancer Society.
The other skin tumor types, squamous cell carcinoma and basal cell carcinoma, are derived, as their names suggest, from other cell types in the skin. They are much more common than melanoma but do not get the same attention as fortunately they have very low mortality rates. However, these types of tumor can occur repeatedly and in new places. Also, the treatments can cause discolouring scars, for example, on the face, as even these tumors are mainly caused by the sun.
Squamous cell carcinoma and basal cell carcinomas are mainly located in areas exposed to the sun and usually appear as small bumps in the skin or wounds that do not heal for a couple of months. The tumors are treated many times directly because they have a typical appearance for the habitual eye, but sometimes if the diagnosis is uncertain, a sample is taken to ensure proper diagnosis. Treatment may include surgery, freezing, photodynamic treatment (PDT), various cytostatic creams or a combination of these.