The process of uterine cancer

When the cervical epithelial metaplasia process is active, stimulated by certain external carcinogens, or the transition zone changes repeatedly, the active immature cells or proliferating squamous epithelium in the transition zone may develop in an atypical direction.

Characteristics of atypical hyperplasia: poor cell differentiation, disordered arrangement, nuclear hyperchromasia, nuclear atypia, and nuclear division phase. This change is called squamous epithelial atypical hyperplasia cervical dysplasia. Part or most of the cervical epithelial cells are replaced by atypical cells of varying degrees, and the abnormal differentiation gradually develops from the base to the entire epithelium. According to the degree of epithelial abnormality, cervical atypical hyperplasia is divided into three degrees (grade III).

Mild (grade I) Lesions are limited to the lower 1/3 of the epithelium

Moderate (grade II) Lesions are limited to the lower 2/3 of the epithelium

Severe (grade III) lesions involve almost the entire epithelium (upper 1/3).

When the causes that induce atypical hyperplasia continue to exist, these lesions can continue to develop into carcinoma in situ and finally form invasive cancer.

Cervical carcinoma in situ (CIS): refers to the cancerous transformation of cervical epithelial cells, but the basal layer has not been penetrated and the stroma has not been infiltrated. It is also called intraepithelial carcinoma. Since the 1960s, studies such as electron microscopy, cell culture and cell genetics have found that cervical atypical hyperplasia cells are similar in nature to carcinoma in situ. It is believed that the two are a series of changes in the same lesion, but the difference is in degree. Therefore, Richart proposed the concept of cervical intraepithelial neoplasia in 1967: cervical intraepithelial neoplasia (CIN). This name includes all precancerous lesions and carcinoma in situ, reflecting the continuous development of the pathological process in the occurrence of uterine cancer. It has been widely used by scholars at home and abroad.

CIN is divided into three levels according to the severity of the lesion:

CINI level: mild dysplasia

CIN II: moderated dysplasia

CIN III: severe dysplasia + severe CIS + carcinoma in situ

All grades have a tendency to develop into invasive cancer. Generally speaking, the higher the grade, the greater the chance of developing into invasive cancer. According to relevant statistics, mild to moderate grades have a 10% to 15% chance, and severe grades have a 75% chance of developing into cancer (this is not fixed and can be reversed).