The cancer that we say in the mouth is also called malignant tumor in clinical. There are many types of cancer. It is not that all cancers represent death. According to the degree of differentiation of cancer cells, they are divided into low differentiation. , Medium differentiation, high differentiation and carcinoma in situ, so what is cancer in situ?

　　Cancer in situ is also known as Bowen''s disease, or intraepithelial carcinoma. It is more common in the elderly and occurs at the junction of the cornea and conjunctiva. There is a clear boundary between the tumor and adjacent normal tissues. The development is slow and can be limited to the intraepithelium within a few years. Pathological examination shows an irregular epidermal hyperplasia, which belongs to true intraepithelial carcinoma. In the slices, epithelial cell polarity is disordered. Normal epithelial cells are replaced by many alien or multinucleated singular cells. Common keratinized and incompletely shaped split phases. The epithelial basement membrane is intact and the prognosis is generally good.

　　 Generally speaking, the epithelial malignant tumor is confined to the skin or mucous membrane, and has not invaded the dermal tissue through the basement membrane under the skin or mucous membrane, nor has it infiltrated or metastasized. Therefore, carcinoma in situ is sometimes referred to as "pre-invasion cancer" or "stage 0 cancer". Strictly speaking, it is not really a cancer at all.

　　 Cancer is terrible because it will metastasize, and it is difficult to completely control after metastasis, and carcinoma in situ does not have this feature of metastasis. Therefore, if it is found in the stage of carcinoma in situ, it is a relatively mild disease, and the treatment plan is relatively simple. It is usually directly removed without chemotherapy. It is completely curable, and the cost is relatively cheap, usually medical insurance can directly cover.

　　Carcinoma in situ is located at the junction of the conjunctiva. It is raised, has a rough surface, has many blood vessels, and has obvious boundaries with adjacent tissues. Surgical treatment is based on topical antibiotics and corticosteroid eye drops, supplemented by nutrition and supportive treatment, and cyclosporin A can be applied locally or systemically when necessary.