skin cancer
Introduction
Introduction to skin cancer The incidence of skin cancer in China is very low, but it is one of the common malignant tumors in white race, more than the sum of all other malignant tumors. The incidence of skin cancer in southern Australia is at least 650/100,000. Among Caucasians in the United States, the incidence of skin cancer is as high as 165/100,000, which is 100 times higher than that in China. Basal cells in skin cancer Cancer is the most common, accounting for more than 60%. The early manifestations of various types of skin cancer are mostly erythematous lesions, accompanied by scaly desquamation or molting. It is difficult to distinguish histological types from the naked eye, and it is easy to be confused with benign skin diseases such as psoriasis and eczema. It is often necessary to take a pathological examination to confirm the diagnosis. Regardless of surgery, radiotherapy or other treatments, it has a good effect on skin cancer, and the cure rate can be above 90%. basic knowledge Sickness ratio: 0.1% Susceptible people: no specific population Mode of infection: non-infectious Complications: cervical lymph node metastasis
Cause
Causes of skin cancer
Daily exposure and UV exposure (25%):
There is enough evidence to support ultraviolet radiation. The interaction between human melanin protection and immune system function leads to the occurrence of skin cancer. The human skin is measured in sunlight. The most exposed parts of the skin are the head, face, neck, and hands. Squamous cell carcinoma occurs almost entirely in these parts. The carcinogenic mechanism of ultraviolet light may be that actinic changes the structure of cellular DNA, destroys the structure of active antigen on the surface of lymphocytes, and reduces the immune function of the body. The joint participation of cancer factors leads to the occurrence of skin cancer.
Chemical carcinogens (18%):
About 100 years after Percivall first described the report of chimney sweeping scrotal skin cancer, it was discovered that workers who are exposed to arsenic, tar and asphalt are prone to skin cancer. Chemical carcinogenesis can be divided into two periods, namely Period and assisted long-term, the results from the beginning to the end are closely related to the limits of exposure to specific substances or carcinogens, which are irreversible, cell changes are related to heredity, and long-term exposure to contact materials is required, which is related to the interval. It can be reversed without exposure for a long time, and no cancer occurs. The interval between the initial period and the long-term help period is very important. There are two kinds of results, that is, skin cancer is formed or not.
Ionizing radiation (14%):
In the past, skin cancer occurred on the basis of radiation-induced dry skin caused by radiation workers neglecting protective measures. In recent years, due to improvements in radiology equipment and advances in radiology, in particular, various protective measures have been strengthened. Sexual skin cancer has largely disappeared, but in some patients undergoing radiation therapy, cases of skin cancer in the radiation field can still be seen after several years.
Chronic irritation and inflammation (16%):
Malignant skin tumors can occur and develop in chronic scars of scars, forming fistulas and sinus. Some Asian people like to chew tobacco or betel nut, so squamous cell carcinoma is easy to occur in the mouth or lips.
Other (13%):
In the stage of immunosuppression, patients with low immune system function can develop skin cancer. For example, the application of immunosuppressive agents can promote the occurrence of skin cancer, viral carcinogens, many viruses can cause cancer in animal hosts, and many human papillomaviruses in humans. The subtype can induce skin cancer.
Prevention
Skin cancer prevention
Prevent the occurrence of skin cancer
1. In daily life and work, try to avoid long-term exposure to harmful chemicals such as asphalt, tar, arsenic, benzopyrene, etc. These chemicals have strong carcinogenicity.
2. To prevent prolonged skin exposure, the third point is to pay attention to ionizing radiation, which is mainly for radiologists. Patients with precancerous lesions such as actinic keratosis and xeroderma pigmentosum should be treated as soon as possible to fight for skin cancer at the time of germination.
3. It is necessary to strengthen physical exercise and improve physical fitness. For example, the Chinese medicine practitioners say: "There is no way to live in the righteousness."
Complication
Skin cancer complications Complications of cervical lymph node metastasis
The disease develops rapidly and is destructive. It can penetrate into connective tissue, cartilage, periosteum and bone. Regional lymph node metastasis can often occur, and visceral metastasis can occur in the late stage. Especially the squamous cell carcinoma of the mucosa is easy to metastasize.
Symptom
Symptoms of skin cancer Common symptoms Increased facial wrinkles, erythematous rash, wounds, crusting, skin pain, erythema nodules, skin, mild erosion, skin fragility, long-lasting red skin
1. Skin ulcers that have been cured for a long time or when there is a good time or a small amount of bleeding.
2. Where there is bleeding, ulceration or asymmetrical nodular protrusion in solar keratosis.
3. When the skin or old sore that has been irradiated by the sun in the past, or when there is a ulceration or nodular protrusion at the sinus.
4. The long-lasting red skin sputum, which shows the possibility of being alert to cancer in situ when it is mildly erosive.
Examine
Skin cancer examination
Common examinations of skin cancer include physical examination, blood routine examination, immune function examination, pathological examination, X-ray examination, B-ultrasound examination, CT examination, and radionuclide examination.
Diagnosis
Diagnosis of skin cancer
Pay attention to the identification of the following diseases
1. Basal cell carcinoma and squamous cell carcinoma : The main part of basal cell carcinoma is the face, especially the nose, forehead, eyes, ankle and upper lip. The damage develops slowly, the local part is often not congested, and the surface is scarred and hornless. The edge is rolled up, waxy translucent, inflammatory reaction is not or slight, metastasis is rare, squamous cell carcinoma can occur in any part, especially skin and mucous membrane junctions and limbs, lower lip, nose, ear, back and genitals It often occurs in chronic skin lesions, the damage develops rapidly, local congestion is obvious, or there are dilated capillaries around and on the surface, keratinization is obvious, the edges are high and hard, the inflammatory reaction is significant, and lymph node metastasis is easy to occur.
2. Seborrheic keratosis: also known as senile sputum, occurs in men over 50 years old, mostly in the face, neck, chest, back and back of the hand, the damage is slightly rounded or oval rounded scorpion The rash is yellow, yellowish brown to black, with clear boundaries, soft texture, slightly rough surface, and oily scales. The number of rashes is variable, often, and seborrheic keratosis can persist forever without malignancy. Individual lesions in a small number of patients can progress to basal cell carcinoma, and histopathological examination can aid diagnosis.
3. Skin in situ cancer (Bowen's disease): damage occurs in the trunk and buttocks, can be single or multiple, typically a well-defined scaly maculopapular rash, can gradually expand, or merge with each other, the damage can range from a few millimeters to several Cm does not equal, the surface is covered with scales or desquamation, brown to gray hard sputum, not easy to peel, slow development or no obvious changes in the long term, sometimes the central part can partially subside or scar formation, and new damage appears nearby, generally not It becomes an ulcer and histopathological examination is helpful for diagnosis.
4. Discoid lupus erythematosus: more common in middle-aged men and women, damage to the initial hairy small papules, gradually enlarged plaque, dry nature, surface keratin proliferation, hair follicle mouth expansion, containing horny spurs, atrophic plaque, no ulceration, More congested on the edge, occurs in the face of the butterfly-like distribution, erythrocyte sedimentation rate, rheumatoid factor, anti-nuclear antibodies, histopathology can help identify.
5. Keratosis acanthoma: more middle-aged men, mostly on the face, especially the cheeks and nose, while the limbs and trunk are extremely rare, the damage is a solid hemispherical tumor standing on the skin, like a reddish acne or The skin is similar in color, the edge is raised, the central depression is crater-shaped, and contains a horny sputum. The disease develops rapidly, but it does not continue to develop after reaching a diameter of about 2 cm. It can be self-contained within 2 to 6 months. Shrinking, natural healing, leaving atrophic scars.
6. Paget's disease: It often invades the unilateral nipple and areola of women over 40 years old. In the early stage, it is only a small scaly erythema of the nipple. The boundary is clear, gradually and its adjacent skin, the surface is easy to be eroded, and it is eczema after scratching. Changes, the damage is slow, no self-healing tendency, occasionally found in other areas of the apocrine glands other than the breast, such as the armpits, external genitalia, perianal, lips, nose, etc., histopathological examination shows scattered or agglomerated Paget cells in the epidermis See this cell to confirm the diagnosis.
7. Metastatic skin cancer: It is caused by the metastasis of other organs from the primary cancer to the skin. It is usually multiple, and there are symptoms and signs of primary cancer in other organs.
