Nevus is a type of skin tumor which develops from melanocytes, the cells responsible for skin pigmentation. There are several kinds. We can distinguish pigmented nevi, common or banal and commonly called moles. These are the most frequent and their origin is disputed. Many variations are described depending on where they grow and their color. Common nevi exist in all human beings from an early age and increase in number until the age of 40 (on average) before declining in number. A particular kind of nevus that grows not from the melanocytes, but from the sebaceous glands is called nevus sebaceous, whose appearance is earlier and evolution different.
The different classifications of nevi are:
- pigmented nevi, "classic" moles;
- blue nevi;
- achromic moles, which are the same color as the skin;
- congenital nevi, present at birth;
- sebaceous nevi, which appear in the first months of life and mostly on the face or scalp.
The diagnosis is clinical and the advice of a dermatologist should be sought when in doubt. Some types of nevi require monitoring, which is the case of some common nevi that can evolve into melanoma
or certain sebaceous nevi. The analysis of nevi after ablation allows for their identification.
The removal of a nevus is not systematic and should be reserved for doubtful forms. Some unsightly moles can also be removed.