This was originally a general study from the AJOG, but it was of great interest to me and is presented for your reference. The study was conducted between January 2005 and August 2009 and included a total of 683 patients younger than 25 years with CIN1 or CIN2, divided into three groups: 106 patients with CIN2 that regressed spontaneously within 2 years, 299 patients treated for CIN2, and 278 patients with CIN1 under conservative observation. After a median follow-up of 4 years, the percentage of patients in these three groups who developed high-grade endothelial lesions (CIN2/3, HSIL, ASC-H) within 2 years was 17% (18/106), 12% (32/278), and 4% (13/299), respectively. Of these, there was no significant difference between patients with CIN2 that regressed spontaneously within 2 years and those with CIN1 under conservative observation (P = 0.83), while patients treated for CIN2 had the lowest risk of recurrence (P = 0.01). See the table below for details. Accordingly, the authors concluded that those cases in which CIN2 was able to regress spontaneously had a biological behavior similar to that of low-grade lesions. Therefore, the management options for young patients under 25 years of age with CIN2 may require further discussion and discretion.