[Preinvasive lesions and their treatment].

Pre-invasive lesions of the uterine cervix are histological abnormalities corresponding to dysplasias and also called cervical intraepithelial neoplasias (CIN). These lesions are more or less severe, but they do not cross the basal membrane. The histological diagnosis rests on disorders of maturation and differentiation and on the presence of nuclear abnormalities and abnormal mitotic activity. No cytological, histological or colposcopic criteria are available to assess the evolutive potential of these lesions. A CIN III lesion has a 60-70 p. 100 risk of becoming a cancer. One-third of pure condylomas are thought to be due to an oncogenic virus. The diagnosis of CIN rests on colposcopy, cytology and histology. Depending on the severity of the lesion, treatment consists of local destruction by cryotherapy, electrocoagulation or laser vaporization; conization may also be used. Laser vaporization is not contra-indicated in CIN III. Treating cervical dysplasias is the best way of preventing cancer.