Nevus

A nevus is a mark on your skin.

Some marks are there when you are born. Others come later in life. These marks can be dark. Some can even be light.

Marks can change the color of your skin. This happens when the color parts of your skin change. Some marks are even in your mouth.

Most marks are safe and harmless. Doctors can look at them with their eyes. They may use a tool to see better.

Some marks might need a doctor to help. They can watch them or use tools to fix them.

It is good to know your skin.

A nevus is a mark on your skin or inside your mouth.

People often call them moles or birthmarks. Some people have them when they are born. Others get them later in life.

These marks happen when skin cells grow in a certain way. Some marks have extra melanin. Melanin is the part that gives skin its color. These marks look dark. Other marks have less melanin. These marks look light.

There are many kinds of nevi. Some are in the top layer of skin. Others are in the deep layer called the dermis. Some are made of extra blood vessels.

Doctors look at these marks with their eyes. They may use a tool to see them better.

Most marks are harmless. But some marks can be a sign of skin cancer. A doctor might take a tiny piece of skin. They look at it under a microscope. This is called a biopsy. They can also use cryotherapy. This is a way to treat a mark using cold. Doctors watch marks to keep you safe.

A nevus is a medical term for a mark on the skin or inside the mouth.

These marks are often called moles or birthmarks. Some people have them from the day they are born. Other people get them later in life. They can be found on the skin or the mucosa, which is the soft lining inside the mouth.

Most marks that stay since childhood are harmless. However, doctors study them to make sure they stay safe.

These marks happen when certain cells grow in a specific way. Many nevi involve melanocytes, which are the cells that make melanin. Melanin is the pigment that gives your skin its color. Some marks have extra melanin, so they look dark or colorful. Other marks have less melanin, making them look light. Some marks do not involve color at all. They might come from extra oil glands, sweat glands, or even blood vessels. These are called vascular nevi.

Scientists and doctors use many names to group these marks. For example, a blue nevus is often small and flat. It can look blue-black in color. Some marks are categorized by how deep they go in the skin. A junctional nevus is in the epidermis, the top layer. An intradermal nevus is in the dermis, the deeper layer. A compound nevus sits in both layers at once. There are also large marks called congenital melanocytic nevi. These are measured by size, such as small marks under 1.5 cm or large ones over 20 cm.

Doctors use special tools to look at these marks closely. They often use their naked eyes or a tool called a dermatoscope. For more detail, they might use computerized imaging. If a mark looks suspicious, a doctor may perform a biopsy. This means they take a tiny sample of skin to look at under a microscope. This helps them see if the cells are healthy or if they are a type of cancer called melanoma. In children, doctors look for specific signs like bleeding or bumps to stay safe.

There are many ways to manage a nevus depending on what it is. Some marks only need observation, which means a doctor just watches them over time. Other marks might be treated with cryotherapy, which uses extreme cold.

Doctors can also use chemical peels, lasers, or even surgery to remove them. They might choose these options if a mark is itchy or looks a certain way. The goal is always to keep the skin healthy and help the person feel good.

A nevus is a medical term for a visible, permanent lesion on the skin or mucosa. The mucosa is the soft, moist lining found in areas like the mouth or genital regions.

The word comes from the Latin word for "birthmark." However, a nevus is not always present at birth. Some are congenital, meaning they are there from birth, while others are acquired later in life. People often use common names like "mole," "beauty mark," or "birthmark" to describe them. These common names are helpful, but they do not distinguish between the many specific types of nevi.

Many nevi are caused by changes in melanocytes. These are the cells that produce melanin, the pigment responsible for skin color. Some nevi are hypermelanotic, meaning they contain increased amounts of melanin. These often appear dark or colorful. Other nevi are hypomelanotic, which means they have decreased melanin and appear lighter.

Beyond pigment cells, some nevi involve the growth of other tissues. Epidermal nevi involve excess growth of cells like those in sweat or oil glands. Connective tissue nevi involve abnormalities in collagen within the dermis, the deep layer of the skin. Vascular nevi involve the excess growth of blood vessels, such as capillaries. One example is the nevus simplex, often called a stork bite.

Doctors classify melanocytic nevi by where the cells are located in the skin layers. A junctional nevus is found in the epidermis, the outermost layer. An intradermal nevus is located in the dermis, the deeper layer. A compound nevus involves both the epidermis and the dermis. There are also many specific types of pigmented nevi. A blue nevus is typically flat, smaller than 1 cm, and blue-black in color. A nevus spilus features dark speckles on a tan-brown background. Atypical or dysplastic nevi are characterized by irregular borders and variable pigmentation. These require a histological examination, which means looking at the tissue under a microscope, to diagnose.

Congenital melanocytic nevi are often categorized by their size at birth. These lesions usually grow in proportion to the body as a person ages. Small nevi are less than 1.5 cm. Medium nevi are between 1.5 cm and 19.9 cm. Large nevi are 20 cm or greater. This size categorization is very important for medical safety. Large congenital melanocytic nevi are associated with an increased risk of melanoma. Melanoma is a serious type of skin cancer. Because of this risk, doctors monitor these growths very closely.

Diagnosing a nevus involves looking at the lesion's physical features. Clinicians often use the naked eye or a tool called a dermatoscope. For more detail, they may use computerized dermoscopy and image analysis. If a lesion looks suspicious, a doctor might perform a biopsy. This involves taking a sample of the skin for histopathological examination. This process allows experts to detect unique cellular features under a microscope. In adults, doctors use the ABCDE criteria to check for melanoma. This stands for asymmetry, border irregularity, color variegation, diameter greater than 6 mm, and evolution. For children, doctors use modified criteria, such as looking for bleeding, bumps, or uniform color.

Managing a nevus depends on its specific type and any diagnostic uncertainty. Some nevi are known to be benign, or harmless, and only require observation over time. Other nevi might be treated if they cause irritation, such as itching, or if they ulcerate.

Doctors have several ways to treat or destroy a nevus. They may use cryotherapy, which uses extreme cold to freeze the tissue. Other methods include chemical peels, dermabrasion, or laser ablation. In some cases, a doctor may perform surgery to remove the lesion. The choice of treatment often depends on cosmetic concerns or the risk of malignancy.

Nevi are also linked to several dermatologic syndromes. These are groups of medical signs and symptoms that occur together. Examples include Basal cell nevus syndrome and Dysplastic nevus syndrome. Other examples are Blue rubber bleb nevus syndrome and Epidermal nevus syndrome. Understanding these connections helps doctors see the bigger picture of a patient's health. By studying the specific cells and patterns of a nevus, medical professionals can distinguish between a simple birthmark and a more serious condition.