Pigmented nevus can be divided into three types: borderline nevus, intradermal nevus and mixed nevus. The nevus cells and nevus cell nests are mainly located between the epidermis and dermis. It is characterized by flat or slightly high skin surface, unclear boundary, smooth surface, hairless color, light yellow, blue or black, which can be found in any part of the body, especially in teenagers and children. Intradermal nevus, that is, nevus cells and nevus cell nests are all gathered in the dermis, often flat or verrucose above the epidermis, dark brown or dark black in color, and even hairy. It is a common pigmented nevus in adults, with clear boundaries and not easy to become malignant. In mixed disease, nevus cells and nevus cells are embedded in the deep epidermis and also live in the dermis, which is called mixed disease. Common diseases, such as prominent skin surface, long hair, diffuse surroundings, different colors and unclear boundaries, belong to the composition of borderline nevus. Borderline nevus gradually changed into intradermal nevus from small to large, and mixed nevus was rarely seen in the elderly. Both mixed nevus and borderline nevus may become malignant.

What circumstance can make pigmented nevus malignant?

Pigmented nevus becomes malignant melanoma, and its course of disease progresses rapidly, which is quite dangerous. Whenever the diagnosis is clear, it is mostly late. Generally, borderline nevus and mixed nevus have the possibility of malignant transformation: they often live in palms, soles, scalp, lips, cheeks and neck, and moles that are easily worn and chronically stimulated or injured are prone to malignant transformation; The color quality of red lips, glans penis and labia minora may also deteriorate. In addition, some improper treatments, such as chemical corrosion or cauterization, can also induce malignant transformation.

What are the manifestations of malignant transformation of pigmented nevus?

After long-term chronic stimulation or improper treatment, pigmented nevus often appears that the range of diseased nevus increases rapidly, or the color deepens rapidly although the range changes little, and the surrounding boundaries are unclear, often showing different shades of light yellow. After the hair on the mole falls off, or the surface breaks and bleeds to form an ulcer; Point-shaped satellite nevus with the size of a needle tip appeared around the lesion; Or local lesions accompanied by strange itching and pain. If the above-mentioned l-2 manifestations are found, we should pay attention to them, closely observe the development of the disease, make timely and accurate judgments, formulate corresponding treatment measures and actively treat them.

What is the purpose of pigmented nevus treatment?

At present, the treatment of pigmented diseases is mainly from the perspective. As a result, many patients with pigmented nevus do not go to the hospital for dermatology or cosmetic surgery, but hope for "beauty salons", regardless of their prognosis. Therapists and patients can consider the following points: What kind of mole is your long mole, and does it have a tendency to become malignant? What is the nature of your treatment? Is it chemical corrosion, cauterization, surgery or something else? What is the reliability and feasibility of this method? Will it cause new complications, such as scar formation, incomplete disease clearance, and even the spread of moles caused by this treatment? In order to eliminate the adverse consequences of the treatment of pigmented nevus, many people go to the hospital first, and then find a cosmetic plastic surgeon for treatment, which can not only achieve the purpose of getting rid of the disease, but also achieve the effect of beauty, and can also determine whether the nevus is benign or malignant through examination. It can be seen that it is imprudent and unscientific to rot all moles, burn them regularly and remove them at will. It is really necessary and important for surgeons and plastic surgeons to see more.

How did pigmented nevus become malignant melanoma?

Malignant melanoma is usually borderline nevus or mixed nevus, which is often induced by long-term chronic stimulation or improper treatment. Once it happens, it is very dangerous. It spreads rapidly mainly through lymphatic route and is very difficult to deal with. The treatment principle of malignant melanoma or nevus with malignant tendency is: completely and thoroughly remove black melanoma and its surrounding normal skin and swollen lymph nodes through surgery. Usually, soybean-sized melanoma must be cut at the edge of the tumor or nevus about 2-5 cm beyond the normal skin, and lymph node dissection is needed for those with lymph node metastasis. After excision, the wound can be sutured directly, of course, the tension should not be too great. If it can't be sutured directly, it can be repaired with local flap. If melanosis or melanoma with malignant tendency is mainly removed by surgery, the incision should be at least 1/2 tumor diameter away from the tumor or nevus margin. Lymph node metastasis is often found, and lymph node dissection is undoubted. It is generally better to repair the wound with skin graft and skin flap after operation. After operation, we also closely observed whether there were moles and lymph node metastasis. It is also very important to send the excised tissues, including lymph nodes, for pathological examination.

What methods are there to treat pigmented nevus at present?

As far as the treatment of pigmented nevus is concerned, we must first make a clear diagnosis, or expand the treatment ability, conditions and operators of excision. Methods mainly include non-surgical methods and surgical methods:

The non-surgical methods are as follows: cryotherapy: liquid nitrogen cryotherapy is the most widely used. It uses the characteristics of liquid nitrogen, which is non-flammable, non-explosive and low boiling point (boiling point is-196℃), to freeze the diseased tissue for a very short time (about 30-60 seconds), and then thaw it in a few minutes, resulting in swelling and pain of the frozen tissue, water sores in l-2, water cancer drying up in L-2 weeks and scabbing in 3-4 weeks. Tumors can generally be cured once, and large and thick tumors need to be frozen several times to be cured; Electric burning or baking: it is widely used in the beauty industry at present. Electrocautery mainly applies the principle of electric heating, that is, electric heating and high temperature cautery are used to coagulate and carbonize the diseased tissue and remove it. The principle of electric drying is to generate a spark with adjustable intensity at the moment when high-frequency current contacts the diseased tissue, and quickly destroy, dry, solidify and carbonize the diseased tissue to remove it, thus achieving the purpose of removing symptoms and beautifying; 50% triazole carbonic acid deep solution is also an applied cauterization therapy.

Surgical method: surgical resection of part, most or all of the diseased tissues. Small nevus can be removed and sutured directly. If it can't be sutured directly, the benign nevus will be removed in the center of the nevus in stages, completely and thoroughly. According to the location and size of the lesion, the wound surface will be covered with local skin flap, transferred skin flap or skin graft after resection.

What are the advantages of non-surgical treatment of pigmented nevus?

The biggest advantage of non-surgical treatment of pigmented nevus is that it is less painful, and it has a good effect on superficial, small and non-malignant pigmented nevus, sometimes leaving no trace. But it also has its own obvious shortcomings: for example, it is impossible to analyze pathological tissue slices to judge whether the lesions are benign or malignant. Secondly, for a wide range of lesions, the thoroughness of treatment and postoperative appearance are often not as good as surgical treatment, and of course the scope of application is limited. The biggest advantage of surgical treatment is that the diseased tissues including metastatic lymph nodes can be completely removed. At the same time, after pathological examination, the nature of the lesion can be accurately understood. Pigmented diseases of any type and any part can be well treated. Of course, there are some fly in the ointment. If you need certain conditions, certain skills and all facilities and means to ensure the success of the operation, you will have to endure some pain, and patients with scar constitution will also have obvious scars.

What kind of pigmented nevus should be treated surgically?

The surgical indications of pigmented nevus are as follows: the scope of pigmented nevus is slightly larger and in the exposed part, with an area of more than 0.5 square centimeter; Pigmented nevus has a tear, or the vulnerable parts appear repeatedly, but there is no infection; If the pigmented nevus has been broken, but the infection has not been treated in time, but the surrounding lymph nodes have not grown up, if the lymph nodes have grown up, they should be sent alive, and the nevus can be locally removed after it is determined that it is not melanoma. If there are melanoma changes in lymph nodes, it is considered that the resection range of melanoma exceeds the edge of tumor tissue by more than 5 cm, and the relevant lymph nodes should be removed. It is clear that it is melanoma or giant melanocytic nevus, and the tumor tissue must be sent for examination after operation; Older people with pigmented nevus on the head, face, abdomen and back, with unclear boundaries or different shades of pigment, had better be removed and sent for inspection.