Cryosurgery for intraepithelial neoplasia of the cervix.

Cryosurgery was used as the means of therapy in 203 patients with intraepithelial neoplasia of the cervix. One hundred and ten patients were diagnosed by colposcopy, directed biopsy, and endocervical curettings. The histological diagnosis varied between mild dysplasia and carcinoma in situ. Carbon dioxide gas was used as the refrigerant. Cryosurgery was effective in 96% of the 203 patients treated. The main causes of failure were: lack of colposcopy, endocervical involvement, the size of the lesion, single freeze, and severity of the lesion. False-negative Pap smear rates were 12.8%. The results suggest that carefully selected patients with early intraepithelial neoplasia can be treated adequately by cryosurgery with low incidence of recurrence and without risk and the cost of hospitalization. Meanwhile, this study reaffirms the need to perform biopsies and investigate any abnormal changes of the cervix, even in the absence of an abnormal cytology smear, before any treatment.