What Is a Nevus?

Moles are broadly defined and narrowly defined. The broad sense includes various congenital and acquired melanocyte nevi and sebaceous nevi. The "mole" in medicine is narrowly defined, also known as nevus nevus, pigmented nevus, melanocyte nevus or ordinary acquired melanocyte nevus, excluding congenital melanocyte nevus. Moles are the most common benign skin tumors in humans. They are skin manifestations caused by increased melanocytes in the epidermis and dermis. According to the location of mole cells in the skin, they can be divided into junctional moles, mixed moles, and intradermal moles. Flat lesions suggest junctional moles, slightly higher lesions are mostly mixed moles, and papillomatous lesions and almost all hemispherical and pedicled lesions are intradermal moles.

Basic Information

nickname

Pigmented nevus, nevus cell nevus, cellular nevus, melanocyte nevus

English name

nevus

Visiting department

dermatology

Multiple groups

female

Common causes

A developmental abnormality, melanocytes move to the epidermis and gather locally

Common symptoms

Skin lesions, pimples, nodules, wart or papillary, round

Contagious

no

Mole etiology

Can be caused by a variety of reasons, no conclusion. It is generally believed that the occurrence of moles is related to genetic factors and environmental factors mainly based on ultraviolet rays.

Clinical manifestations of moles

Often appear after two years of age. It can occur on the skin and mucous membranes of any part of the body. The lesions are flat or slightly raised macules or maculopapular rashes, which can also be hemispherical, papilloma-like, or pediculated, with a smooth surface, with or without hair, and the number can be single, several to dozens. Due to the different types and contents of pigments in the nevus cells, the skin lesions can be brownish brown, blue-black, or black, and the non-pigmented skin lesions are mostly skin-colored. According to the location of mole cells in the skin, they can be divided into junctional moles, mixed moles, and intradermal moles. Flat lesions suggest junctional moles, slightly higher lesions are mostly mixed moles, and papillomatous lesions and almost all hemispherical and pedicled lesions are intradermal moles. The disease progresses slowly and there are no conscious symptoms.

Atypical moles may become malignant, such as very dark moles, uneven pigments, uneven or irregular edges, unclear borders, left-right asymmetry, and statistically greater than 5 mm in diameter. Moles that grow in the nail groove, nails, extremities, oral mucosa, conjunctiva, vagina, and foreskin are more likely to become malignant melanoma than moles elsewhere.

Mole check

Histopathological examination revealed nested, non-dendritic nevus cells in the skin.

Mole diagnosis

Diagnosis is usually made clinically, and pathological examination is performed for those suspected of malignant changes.

Mole differential diagnosis

Differentiated from diseases with pigmented skin lesions, such as senile dark spots: It occurs in exposed parts of the body in middle-aged and elderly people, such as the cheeks, neck, back of hands, and forearms, etc., and they are mostly scattered in tan, showing an area size Equally small round, oval or irregularly shaped smooth or slightly higher than skin patches. Histological examination showed that normal melanocytes increased without malignant changes.

Mole complications

May be complicated by infection. Most growth has been slow or has not changed for many years, but rarely spontaneous regression. Individual types of moles may also become malignant, thereby endangering their lives.

Mole treatment

Generally does not require treatment. Boundary moles and mixed moles that occur in the rubbing areas such as palms, waists, armpits, and groin should be considered for surgical removal when: the volume suddenly increases; the color becomes black or mottled; the surface appears eroded , Ulcers, bleeding or swelling; Conscious pain or itching; Satellite lesions appear around. Laser treatment is also available.