This is the commonly used medical terminology of tumor pathology, and these are introduced as follows: hyperplasia: generally refers to the increase of tissue cells, often accompanied by cellular hypertrophy, which is under the action of certain stimulating factors to cause physiological or pathological changes in tissues and cells, in the covered epithelium, it is often the thickening of epithelial tissues and increase of cells; in the mesenchymal tissues, it is often the increase of cells, tightly arranged and so on, but there is no anisotropy. Once the irritating factor goes, it can return to normal.

Atypical hyperplasia: also known as heterogeneous hyperplasia, mesenchymal change or poor nuclear structure, etc. It can be seen in any tissues or cells, and its morphology manifests that the nucleus of the cell is relatively enlarged, the nuclear membrane is thickened, the shape of the nucleus is irregular, and the ratio of the nucleus to the pulp is enlarged, but it doesn't have the morphology of the characteristic of the malignant tumor, etc.. It belongs to one kind of pre-cancerous lesion, which can be transformed into malignant tumor from quantitative change to qualitative change under the continued action of certain factors, and may return to normal state if certain factors are removed. According to the degree of lesions, atypical hyperplasia is generally classified as mild, moderate and severe. Severe hyperplasia is precancerous.

Carcinoma in situ: also known as intraepithelial carcinoma, pre-invasive carcinoma. When the atypical hyperplasia of epithelial cells develops further, the heterogeneity of cell nuclei becomes more obvious, the nuclear shape is irregular, the nuclear membrane is thickened, the chromatin is coarsened, the nucleolus is protruding, and the mitotic division is increased, and this heterogeneous epithelial tissue has already involved the whole epithelium, but has not infringed on the basement membrane. It is the earliest cancer and is irreversible. Chemotaxis: It usually refers to a kind of cell or tissue, which changes from one kind of tissue to another under the action of some factors, for example, when the cervix is heavily eroded, the columnar epithelium or glandular epithelium that covers the cervical canal can be transformed into squamous epithelium, which is called squamous epithelial chemotaxis.

It is generally believed that tissue chemosis, usually for the protective response of organs or tissues, this squamous epithelial chemosis cancerous opportunity is rare, generally should not be treated as precancerous lesions. Tumor-like lesions: some tissue growths, whose appearance is similar to tumors, but different from true tumors, and sometimes difficult to distinguish, this is a large group of proliferative lesions that appear to be tumors, such as dermatomas, keloids, fat pads, etc., and some of these tumor-like lesions can be transformed into true tumors, such as pigmented villous nodular synovitis that can be transformed into synovial sarcoma, so this lesion should be dealt with as a pre-cancerous lesion