Incidence of single or associated "CIN III" lesions according to age

The incidence of single or associated CIN III lesions has been evaluated in 520 patients. 48.92 +/- 13.89 years is the mean age of incidence. Atypical metaplasia has the lowest mean age and is the only CIN III lesion to affect patients under 20 and never to be found--individually--after the age of 50. Severe dysplasia reaches its maximum incidence in the fourth decade. Carcinoma in situ has the highest mean age, reaching its maximum incidence in the fifth decade. But when it is associated with atypical metaplasia, the age shifts to the fourth decade. Apparently, these results confirm the role of "precursor" of atypical metaplasia. Severe dysplasia and carcinoma in situ are later stages of the cervical carcinogenesis. Furthermore, the high rate of associated lesions provides further evidence of their similarity and "common origin", with important prognostic and therapeutical implications.