The incidence of basal cell carcinoma has been increasing year by year along with environmental pollution, food safety, work pressure, etc. Based on my clinical experience, I would like to popularize the related knowledge. Basal cell carcinoma Non-melanoma skin cancer (NMSC) is the most prevalent malignant tumor in humans, among which basal cell carcinoma (BCC) is the most common, first described by Jacob in 1827, but only clearly distinguished from other epithelial tumors by Krompecher in 1902. The epidemiological characteristics of basal cell carcinoma are: more male patients than female, and the incidence increases with age. Disease Overview Current studies have linked the development of basal cell carcinoma to multiple genetic variants involved in the Hedgehog pathway, the most common of which are the PTCH1 gene and TP53 gene. Studies have also confirmed the existence of many risk factors associated with the development of basal cell carcinoma, such as inappropriate UV exposure, ionizing rays, light skin tone, stain dry skin disease or sebaceous nevus. It is also important to ask about family history in basal cell carcinoma cases because diseases characterized by basal cell carcinoma, such as nevus-like basal cell carcinoma syndrome, fall under the category of genetic diseases. Clinical manifestations Basal cell carcinoma can occur on the head, trunk and extremities, but mostly occurs on the head and other light-exposed areas. Depending on the color of the lesions as dermatoglyphic or black, they can be classified as pigmented or non-pigmented types. In combination with pathology, the more recognized clinical subtypes are: nodular, superficial, scleroderma-like, cystic, basal squamous carcinoma, micronodular, and Pinkus fibroepithelioma. The most common type is the nodular type, often with a central ulcer, which is then also known as nodular ulcerative basal cell carcinoma, and this type is mostly seen on the head and face. Micronodular and scleroderma-like types are relatively uncommon, but are also seen mostly on the head and face. The most common type of basal cell carcinoma on the trunk is superficial type. Pathological changes The pathological manifestations of different types of basal cell carcinoma are different, but they have common basic features. For example, tumor cells are clustered in nests, with uniform cell morphology and size, rare nuclear heterogeneity, little cytoplasm and basophilic blue staining, similar to basal cells. For example, tumor peripheral cells are arranged in a fenestrated pattern, and due to production, there are often clefts between tumor cell nests and surrounding tissues. Seizing the above features, it is easy to diagnose basal cell carcinoma regardless of whether the cell nests appear as large nodules, micronodules, or stripe-like. Diagnosis and Differential Diagnosis The gold standard of basal cell carcinoma diagnosis is pathology, therefore, biopsy pathological examination must be actively performed for suspected skin masses. A study showed that the accuracy rate of naked eye diagnosis of basal cell carcinoma is only 67.9%, which further supports the importance of pathology. It should be emphasized that the scope and method of excision for malignant skin tumors are very different from those for benign masses, so the diagnosis must be confirmed by pathology first, followed by complete excision. If the order is reversed, it may sometimes interfere with the subsequent treatment. Treatment Basal cell carcinoma is preferred to surgical excision. Since basal cell carcinoma is a continuous invasive growth tumor, metastasis rarely occurs. Evidence-based medical research shows that the 5-year cure rate of primary basal cell carcinoma treated by traditional tumor expansion methods is about 93%. If the basal cell carcinoma occurs in the trunk or extremities and the area is small, it can be considered to be resected with 5 mm expansion and preferably with comprehensive pathological examination of the cut edge after surgery. Advantages of treated BCC The key to clean tumor resection is the extent of resection. For doctors of other disciplines there exists a dilemma that if the extent of resection is too large, they will face the dilemma that the wound cannot be closed or there is a lot of tension after closure. The reason why we dare to use extended resection is that the team’s discipline based trauma repair technology can remove the tumor to the maximum extent and depth. During the resection process, the pathology is always frozen to ensure a clean resection. We use skin graft, skin flap, muscle flap and fascial flap to repair the wound after resection as needed. The technical guarantee lays the foundation for good curative effect. Basal cell carcinoma is also more sensitive to radiation therapy and cryotherapy. If patients cannot undergo surgery due to various objective reasons, radiation therapy and cryotherapy can be chosen. For basal cell carcinoma that is prone to recurrence and aggressive such as sclerosis-like type or micronodular type, additional radiation therapy after surgery is recommended. Basal cell carcinoma should be followed up for more than 5 years after treatment. In general, the prognosis is very good, the recurrence rate is low, and once recurred, it can be operated again, which is rarely fatal.