A growth on the skin is the first sign of a melaniform (melanocytic) epidermal nevus. It can be nodular, located at the junction of the epidermis and the underlying dermis - in the dermoepidermal layer; can be slightly raised above the surface of the skin, as well as intradermal, which is a classic mole - a raised dome-shaped bulge on the skin surface from light brown to dark brown, varying degrees of bulge and size, round or irregular in shape.
There are different types of melaniform nevus, that is, types of moles on the body , the external symptoms of which may differ.
Melanocytic or melanocytic pigmented nevus is an acquired melanocytic nevus that occurs in childhood as brown flat spots 1-2 mm in size, which most often appear on skin exposed to ultraviolet rays. In these nevi, nevocyte nests are located along the dermoepidermal junction.
If the area of the pigmented formation exceeds 10-12 mm, an extensive melanoform nevus is determined. For example, the size of Becker's nevus (hairy epidermal nevus) can be up to 15-20 cm.
Intradermal melaniform nevus or convex mole refers to acquired formations that are localized mainly on the head, neck or upper body. In this case, nevocytes can be limited to the middle layer of the dermis. These intradermal nevi are usually fleshy in shape, can have a leg and develop in three stages: first, the mole grows intensively (and can form a leg), then its growth slows down and stops, after which the formation - as the depth of the dermis increases - begins to decrease and becomes lighter...
The border intradermal nevus is flat and may be gray to brown in color. Also read - Flat moles
For nevus Setton characterized by the appearance of depigmented ring around moles. And the nevus of Jadasson-Tiche (blue epidermal nevus) looks like a dense papule or nodule of blue-gray or blue-black color.
What is a melaniform papillomatous nevus or a verrucous nevus, for more details, see the materials:
A mixed melanoform nevus is determined by the histology of a mole ; in such cases, in one formation, a combination of various nevus cells, as well as connective tissue and dermal elements, is revealed.
Biopsy and histological examination can also reveal an atypical melanoform nevus - a pigmented melanocytic formation on the skin with distinct clinical and histological features in the form of cellular atypia. More details in the article - Dysplastic nevi