Nevi, mostly known as moles, are benign brown lesions that can be either elevated from the surface of the skin or flat. The cause of the lesion is the nodular proliferation of melanocytes, which synthesize melanin, the pigment responsible for the brown color of the mole. Nevi can be congenital or acquired and are usually not dangerous. However, one must be cautious of changes in certain features, such as color (moles can darken or lighten), size (increase by 2mm or more in a year), asymmetrical and uneven borders, thickening, a feeling of burning, tension, tingling, redness of the skin around the mole, or bleeding of the lesion.
If you notice any of the changes listed above, it is important to visit an oncologist, oncodermatologist, or dermatologist. In some cases, changes may be linked to factors such as sun exposure or hormonal changes, which are not necessarily harmful. However, excessive sun exposure can lead to aggressive tumors known as melanomas. Other risk factors for melanomas include UV radiation, chronic skin irritation, exposure to radioactive substances, poor diet, alcohol consumption, smoking, hormonal changes, genetics, light skin (which lacks melanin, affecting skin protection), a high number of moles (more than 50), and immunodeficiency.
The presence of one factor does not usually lead to melanomas, but rather a combination of these factors. Melanomas can vary in shape, color, or size and may be symmetrical or asymmetrical. Melanomas typically lack hair, so sudden hair loss from a mole and a halt in growth may be concerning. An increase in pigment is often observed around the lesion. Melanomas often metastasize to lymphatic and blood vessels. The most important prognostic factor is the depth of invasion; the size of the lesion does not affect the prognosis. These lesions typically metastasize to the bones, liver, lungs, and brain, affecting the prognosis. The final diagnosis is made based on the patient’s medical history, dermatoscopic examination, and an incisional or excisional biopsy if necessary, which may be followed by molecular (BRAF mutation) or radiological tests. It is important to avoid self-treatment. Additionally, it is crucial to remember that removing benign nevi does not affect the risk of malignant transformation, and malignant melanomas must be removed. Early detection of melanomas is essential for a better prognosis.
