[Colposcopic and cytological studies in pretumorous and malignant changes in the cervix uteri]

814 patients with various pathological changes in the uterine neck were subjected to the complex investigation, taking into consideration the fact that all specialists should be equally competent in their fields. Diagnostic errors were analysed in each method of investigation in relation to a histological conclusion in every series of patients. The diagnosis of preinvasive cancer proved to be most difficult. The number of errors was less in microcarcinoma. The organization of large colpocytological centres in big cities is advocated.