Moles are formed by grouping together melanocytes, the cells in the skin that make the substance that pigments it, melanin. "In reality, they have no physiological function, as occurs with warts and other lesions," explains Javier Pedraz, a dermatologist at the San Carlos Clinical Hospital in Madrid. Its importance lies in the possibility that they evolve and give rise to skin cancer. When their appearance changes, they have irregular edges, they become hard, the color is not homogeneous and the diameter exceeds six millimeters, it is necessary to go to the specialist to perform a biopsy. If it turns out to be a melanoma, early diagnosis ensures cure in 95% of cases.
Some studies suggest that between 0.2% and 1.5% of the population has a variety known as congenital melanocytic nevus (CMN) at birth. Although they can be of all sizes, in certain cases CMNs are large, and it has been observed that they can reach up to 20 centimeters in diameter in newborns . "These are more likely to become malignant because of their size and because they have been exposed to solar radiation for longer," says Dr. Pedraz. They are not only located on the skin; there are also internal ones. "They are found behind the spine and even in the brain, but they have no impact on health." Yes, the larger ones can have it. "They are very rare, they are usually located in the trunk and are removed with surgery", adds Pedraz.
