Everyone has moles on their body to a greater or lesser extent, and they have large and small, dark brown patches, or raised pieces. Some people, when they feel itchy, or even just notice the presence of a mole, can't help but want to touch or even scratch.
Experts interviewed
Zhou Xiaohong, Director of Head and Neck Cancer Center, Chongqing University Cancer Hospital
Professor of Plastic Surgery, Zhongshan Hospital, Fudan University Qi Fazhi
Can you pick a mole on your body?
Pigmented nevi, medically called nevus cells or melanocytic nevi, are manifestations of increased melanocytes in the epidermis and dermis. Common black moles, brown moles, yellow moles, etc., are pigmented moles.
Pigmented nevi may become cancerous after trauma, repeated friction, or prolonged exposure to the sun.
Moles with a diameter of 4 mm or more than 6 mm will have an increased chance of developing malignant melanoma if they are randomly scratched and dug; Moles that grow in special parts, such as nasal cavity, oral mucosa, palms, soles, heels, anus, genitals and other 7 parts, are often rubbed and prone to malignant changes.
Li Hang, chief physician of the Department of Dermatology and Venereology of Peking University First Hospital, said that repeated friction stimulation will make pigmented nevi more malignant, and the "repeated friction stimulation" mentioned here refers to picking, pricking, such as moles growing in the beard area, using a razor every day to scrape, often scratching, or often picking moles with nails.
Raised VS flat mole, which is more malignant?
Human skin can be divided into epidermis layer, dermis layer and subcutaneous fat from top to bottom. Whether melanocytic nevi bulge out of the skin surface is mainly related to the skin level where the melanocyte nest is located. According to the skin level where the melanocyte nest is located, melanocytic nevi can be divided into intradermal nevi, junctional nevi, and composite nevi.
Intradermal nevi
A common type of nevi in adults, melanocyte nests are distributed within the dermis. Aggregated melanocytes arch the epidermis, appearing as hemispherical raised skin surfaces, light brown or skin-colored small bumps, smooth surfaces, generally within 1 cm in diameter, and sometimes one or more hairs in the center.
At present, it is believed that the probability of malignant transformation of intradermal nevus is very small, but it is necessary to reduce the stimulation and friction on it and observe whether there is a change.
Junctional nevi
Most of them appear in infants or childhood, melanocytes nests are distributed at the junction of the epidermis and dermis, manifested as round or oval, the border is clear and smooth, dark brown to black, flat patches on the skin surface or slightly raised skin surface papules, diameter is more than 0.6 ~ 0.8 cm, no hair.
After puberty, most junctional nevi turn into intradermal nevi, but junctional nevi that grow on the palms, toes, and vulva can still maintain active hyperplasia and have a chance of malignant transformation. Therefore, the junction nevi in these parts need to pay attention to the morphological changes, avoid inappropriate stimulation, and seek medical attention in time if there are changes.
Mixed moles
Also known as composite nevi, melanocyte nests are not only distributed at the junction of the epidermis and dermis, but also in the upper dermis, so the appearance and characteristics are between the intradermal nevus and the junctional nevi.
What kind of moles to consider getting rid of?
Normal adults can have an average of 15~20 moles throughout the body, most of which are benign and safe, and the following kinds of moles are recommended to be vigilant:
Asymmetry: asymmetrical morphology, or the surface suddenly becomes rough from smooth;
Unclear edges: irregular or blurry edges, burrs or jagged;
Color change: uneven color, can be spotted;
Excessive diameter: diameter greater than 0.6 cm or suddenly enlarged;
Changes: From flat to nodular protrusions, small black dot-like "satellite stoves" appear around them, and there are ruptures, bleeding, etc.
When there is a suspected black mole on the foot, swollen lymph nodes are felt in the ipsilateral groin, or when there is a suspicious black mole on the hand, and the enlarged lymph nodes are felt in the ipsilateral axpit, and the possibility of malignant transformation should be alerted.
It is also necessary to maintain some attention for moles that appear after middle age, are located in the extremities or areas of friction pressure, and are often sunburned on the face.
Whether there is hair growth on the mole cannot be used as a basis for judging the benign and malignant black mole.
The morphological changes of moles are not all caused by malignant diseases, and may also be benign folliculitis, soft fibromas, etc. However, these benign diseases are often characterized and will resolve in the short term.
It is recommended to have a microscopic examination every 3~6 months, especially pay attention to the soles and other parts that are usually difficult to pay attention to, and ask your family to help you check the parts that are difficult to observe such as the back.
At present, plastic surgery mostly uses two methods: laser spot mole and surgical removal. In addition, there are chemical cauterization methods for peeling corrosive drugs, freezing methods using dry ice and liquid nitrogen, and electrolytic electrocautery methods, but it is difficult to achieve one-time thorough treatment.
For specific which method is more suitable, you need to consult a plastic surgeon in a regular hospital. ▲
Editor of this issue: Deng Yu
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