Moles, medically known as nevi, are common skin growths that can appear on any part of the body. They emerge as small spots, often dark brown, formed by clusters of specialized pigment-producing cells called melanocytes. While most moles are harmless, their appearance can vary significantly in terms of color, shape, and size. Many individuals develop between 10 and 45 moles during childhood and adolescence, with some appearing at birth.
Understanding What Moles Are Made Of
Moles are solid structures primarily composed of melanocytes, cells that produce melanin, the natural pigment responsible for skin and eye color. These cells cluster together, forming the visible growth on the skin’s surface or within its layers.
A typical, healthy mole does not contain fluid. Unlike fluid-filled sacs such as cysts or blisters, moles are a dense collection of cells, giving them a firm or soft, but never liquid, texture. Moles can be flat or raised, smooth or wrinkled, and some may even have hair growing from them.
If a mole feels as though it contains fluid, or if it appears to ooze or bleed without injury, this is not characteristic of a common mole. Such a sensation or discharge suggests an atypical change that warrants medical attention. While some benign conditions, like Spitz nevi, can sometimes ooze pus, any perceived fluid content or discharge indicates an alteration in its normal cellular structure and requires professional evaluation.
Recognizing Concerning Mole Changes
Any changes in a mole’s characteristics, including a new sensation of softness or fluid, should prompt evaluation by a healthcare professional. Normal moles typically maintain a consistent appearance, so any noticeable alteration warrants concern. This includes changes in texture, such as becoming lumpy, hard, or scaly.
Skin specialists often use the “ABCDE” rule to help identify potentially concerning mole changes:
A: Asymmetry, where one half of the mole does not match the other.
B: Irregular borders, meaning the edges are ragged, notched, or blurred.
C: Color variations, such as multiple shades of brown, black, red, white, or blue within the same mole.
D: Diameter, with moles larger than about 6 millimeters (the size of a pencil eraser) being more concerning.
E: Evolving changes, which means any change in size, shape, color, or height.
Other concerning signs include a mole that becomes itchy, painful, bleeds, or develops a crust. A new mole appearing in adulthood, especially after age 40, also warrants a check.