Squamous cell carcinoma, also known as epidermoid carcinoma occurs as a malignant tumor of the skin appendage cells, with varying degrees of keratinization of the cancer cells. It is more common in areas covered by squamous epithelium, such as the skin, oral cavity, lips, esophagus, cervix, vagina, etc. In addition, some areas such as bronchus, bladder and renal pelvis are not covered by squamous epithelium, but squamous cell carcinoma can be formed through squamous epithelial metaplasia. Squamous cell carcinoma is related to race. The occurrence of squamous carcinoma in Caucasians is 45 times more than that in non-Caucasians. The incidence of squamous cell carcinoma of the skin is significantly higher in immunosuppressed patients, especially in organ transplant patients. 2.Related to the environment, especially the stimulation of sunlight has obvious relationship, long-term sun exposure and chronic stimulation are the main potential causes, trauma, radiation exposure, tar derivatives can also induce the disease, discoid lupus erythematosus, chronic ulcers, mucosal leukoplakia, burn bruises and long-term untreated sarcoidosis can induce squamous cell carcinoma. Squamous cell carcinoma is often cauliflower-like in appearance, sometimes the cancerous tissue is necrotic and shedding to form ulcers, resulting in malignant odor, and if the cancer cells form deep development, it will form infiltrative growth. Cancer cells can also metastasize to distant sites forming secondary tumors. Squamous cell carcinoma of the skin is red hard nodules in the early stage and later develops into wart-like damage, infiltration, often with ulcers, purulent discharge and foul odor, seen in the temporal, forehead and lower lip of the mouth. Diagnosis To diagnose the disease, pathological examination is needed to take the tissue of the lesion. Microscopically, it can be seen that the proliferating epithelium breaks through the basement membrane and infiltrates into deeper layers to form irregular strip-shaped cancer nests. According to the degree of differentiation of cancer cells, there are high, medium and low differentiation. Highly differentiated squamous cell carcinoma is less malignant, while lowly differentiated squamous cell carcinoma is more malignant. Treatment Surgical resection is the main treatment, and radical resection in the early stage is sufficient, while in the middle and late stage, the combination of surgery, radiotherapy and chemotherapy is good.